From 738b5a42b7e9a41861ad0559aa6603158050d5aa Mon Sep 17 00:00:00 2001
From: mudabbir-ahmad <mudabbira.uk@gmail.com>
Date: Sun, 12 Apr 2026 22:03:20 +0100
Subject: [PATCH] add initial project files including .gitignore, editor
 settings, and Two Sum implementation

---
 .idea/.gitignore         |  10 ++++
 .idea/.name              |   1 +
 .idea/Leet-Code-prog.iml |   2 +
 .idea/editor.xml         | 101 +++++++++++++++++++++++++++++++++++++++
 .idea/misc.xml           |   7 +++
 .idea/modules.xml        |   8 ++++
 .idea/vcs.xml            |   6 +++
 CMakeLists.txt           |  10 ++++
 Easy/TwoSum/TwoSum.cpp   |  20 ++++++++
 Easy/TwoSum/TwoSum.h     |  16 +++++++
 Easy/TwoSum/TwoSum.md    |  39 +++++++++++++++
 11 files changed, 220 insertions(+)
 create mode 100644 .idea/.gitignore
 create mode 100644 .idea/.name
 create mode 100644 .idea/Leet-Code-prog.iml
 create mode 100644 .idea/editor.xml
 create mode 100644 .idea/misc.xml
 create mode 100644 .idea/modules.xml
 create mode 100644 .idea/vcs.xml
 create mode 100644 CMakeLists.txt
 create mode 100644 Easy/TwoSum/TwoSum.cpp
 create mode 100644 Easy/TwoSum/TwoSum.h
 create mode 100644 Easy/TwoSum/TwoSum.md

diff --git a/.idea/.gitignore b/.idea/.gitignore
new file mode 100644
index 0000000..30cf57e
--- /dev/null
+++ b/.idea/.gitignore
@@ -0,0 +1,10 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Editor-based HTTP Client requests
+/httpRequests/
+# Ignored default folder with query files
+/queries/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml
diff --git a/.idea/.name b/.idea/.name
new file mode 100644
index 0000000..684ef01
--- /dev/null
+++ b/.idea/.name
@@ -0,0 +1 @@
+Leet_Code_prog
\ No newline at end of file
diff --git a/.idea/Leet-Code-prog.iml b/.idea/Leet-Code-prog.iml
new file mode 100644
index 0000000..4c94235
--- /dev/null
+++ b/.idea/Leet-Code-prog.iml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module classpath="CIDR" type="CPP_MODULE" version="4" />
\ No newline at end of file
diff --git a/.idea/editor.xml b/.idea/editor.xml
new file mode 100644
index 0000000..ca29dcc
--- /dev/null
+++ b/.idea/editor.xml
@@ -0,0 +1,101 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="BackendCodeEditorSettings">
+    <option name="/Default/CodeStyle/CodeFormatting/CppClangFormat/EnableClangFormatSupport/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/ALIGN_MULTILINE_ARGUMENT/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/ALIGN_MULTILINE_BINARY_EXPRESSIONS_CHAIN/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/ALIGN_MULTILINE_CALLS_CHAIN/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/ALIGN_MULTILINE_EXPRESSION/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/ALIGN_MULTILINE_EXTENDS_LIST/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/ALIGN_MULTILINE_FOR_STMT/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/ALIGN_MULTILINE_PARAMETER/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/ALIGN_MULTILINE_TYPE_ARGUMENT/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/ALIGN_MULTILINE_TYPE_PARAMETER/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/ALIGN_MULTIPLE_DECLARATION/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/ALIGN_TERNARY/@EntryValue" value="ALIGN_ALL" type="string" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/ANONYMOUS_METHOD_DECLARATION_BRACES/@EntryValue" value="END_OF_LINE" type="string" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/BLANK_LINES_AROUND_CLASS_DEFINITION/@EntryValue" value="1" type="int" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/BLANK_LINES_AROUND_DECLARATIONS/@EntryValue" value="0" type="int" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/BLANK_LINES_AROUND_FUNCTION_DECLARATION/@EntryValue" value="1" type="int" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/BLANK_LINES_AROUND_FUNCTION_DEFINITION/@EntryValue" value="1" type="int" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/BREAK_TEMPLATE_DECLARATION/@EntryValue" value="LINE_BREAK" type="string" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/CASE_BLOCK_BRACES/@EntryValue" value="END_OF_LINE" type="string" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/CONTINUOUS_LINE_INDENT/@EntryValue" value="Double" type="string" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/INDENT_ACCESS_SPECIFIERS_FROM_CLASS/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/INDENT_CASE_FROM_SWITCH/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/INDENT_CLASS_MEMBERS_FROM_ACCESS_SPECIFIERS/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/INDENT_COMMENT/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/INDENT_SIZE/@EntryValue" value="4" type="int" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/INDENT_STYLE/@EntryValue" value="Space" type="string" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/INITIALIZER_BRACES/@EntryValue" value="END_OF_LINE_NO_SPACE" type="string" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/INT_ALIGN_EQ/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/INVOCABLE_DECLARATION_BRACES/@EntryValue" value="END_OF_LINE" type="string" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/KEEP_BLANK_LINES_IN_CODE/@EntryValue" value="2" type="int" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/KEEP_BLANK_LINES_IN_DECLARATIONS/@EntryValue" value="2" type="int" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/KEEP_USER_LINEBREAKS/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/LINE_BREAK_AFTER_COLON_IN_MEMBER_INITIALIZER_LISTS/@EntryValue" value="ON_SINGLE_LINE" type="string" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/MEMBER_INITIALIZER_LIST_STYLE/@EntryValue" value="DO_NOT_CHANGE" type="string" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/NAMESPACE_DECLARATION_BRACES/@EntryValue" value="END_OF_LINE" type="string" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/NAMESPACE_INDENTATION/@EntryValue" value="All" type="string" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/OTHER_BRACES/@EntryValue" value="END_OF_LINE" type="string" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/PLACE_CATCH_ON_NEW_LINE/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/PLACE_ELSE_ON_NEW_LINE/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/PLACE_NAMESPACE_DEFINITIONS_ON_SAME_LINE/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/PLACE_WHILE_ON_NEW_LINE/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SIMPLE_BLOCK_STYLE/@EntryValue" value="DO_NOT_CHANGE" type="string" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_AFTER_CAST_EXPRESSION_PARENTHESES/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_AFTER_COLON_IN_BITFIELD_DECLARATOR/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_AFTER_COMMA_IN_TEMPLATE_ARGS/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_AFTER_COMMA_IN_TEMPLATE_PARAMS/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_AFTER_EXTENDS_COLON/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_AFTER_FOR_COLON/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_AFTER_FOR_SEMICOLON/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_AFTER_PTR_IN_DATA_MEMBER/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_AFTER_PTR_IN_DATA_MEMBERS/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_AFTER_PTR_IN_METHOD/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_AFTER_PTR_IN_NESTED_DECLARATOR/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_AFTER_REF_IN_DATA_MEMBER/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_AFTER_REF_IN_DATA_MEMBERS/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_AFTER_REF_IN_METHOD/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_AFTER_UNARY_OPERATOR/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_BEFORE_COLON_IN_BITFIELD_DECLARATOR/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_BEFORE_EXTENDS_COLON/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_BEFORE_FOR_COLON/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_BEFORE_FOR_SEMICOLON/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_BEFORE_PTR_IN_ABSTRACT_DECL/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_BEFORE_PTR_IN_DATA_MEMBER/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_BEFORE_PTR_IN_DATA_MEMBERS/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_BEFORE_PTR_IN_METHOD/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_BEFORE_REF_IN_ABSTRACT_DECL/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_BEFORE_REF_IN_DATA_MEMBER/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_BEFORE_REF_IN_DATA_MEMBERS/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_BEFORE_REF_IN_METHOD/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_BEFORE_TEMPLATE_ARGS/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_BEFORE_TEMPLATE_PARAMS/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_BETWEEN_CLOSING_ANGLE_BRACKETS_IN_TEMPLATE_ARGS/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_WITHIN_ARRAY_ACCESS_BRACKETS/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_WITHIN_CAST_EXPRESSION_PARENTHESES/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_WITHIN_DECLARATION_PARENTHESES/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_WITHIN_EMPTY_BLOCKS/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_WITHIN_EMPTY_INITIALIZER_BRACES/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_WITHIN_EMPTY_METHOD_PARENTHESES/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_WITHIN_EMPTY_TEMPLATE_PARAMS/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_WITHIN_INITIALIZER_BRACES/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_WITHIN_TEMPLATE_ARGS/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPACE_WITHIN_TEMPLATE_PARAMS/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/SPECIAL_ELSE_IF_TREATMENT/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/TAB_WIDTH/@EntryValue" value="4" type="int" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/TYPE_DECLARATION_BRACES/@EntryValue" value="END_OF_LINE" type="string" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/WRAP_AFTER_BINARY_OPSIGN/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/WRAP_AFTER_DECLARATION_LPAR/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/WRAP_AFTER_INVOCATION_LPAR/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/WRAP_ARGUMENTS_STYLE/@EntryValue" value="WRAP_IF_LONG" type="string" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/WRAP_BEFORE_DECLARATION_LPAR/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/WRAP_BEFORE_DECLARATION_RPAR/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/WRAP_BEFORE_INVOCATION_LPAR/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/WRAP_BEFORE_INVOCATION_RPAR/@EntryValue" value="false" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/WRAP_BEFORE_TERNARY_OPSIGNS/@EntryValue" value="true" type="bool" />
+    <option name="/Default/CodeStyle/CodeFormatting/CppFormatting/WRAP_PARAMETERS_STYLE/@EntryValue" value="WRAP_IF_LONG" type="string" />
+    <option name="/Default/CodeStyle/EditorConfig/EnableClangFormatSupport/@EntryValue" value="false" type="bool" />
+  </component>
+</project>
\ No newline at end of file
diff --git a/.idea/misc.xml b/.idea/misc.xml
new file mode 100644
index 0000000..0b76fe5
--- /dev/null
+++ b/.idea/misc.xml
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="CMakePythonSetting">
+    <option name="pythonIntegrationState" value="YES" />
+  </component>
+  <component name="CMakeWorkspace" PROJECT_DIR="$PROJECT_DIR$" />
+</project>
\ No newline at end of file
diff --git a/.idea/modules.xml b/.idea/modules.xml
new file mode 100644
index 0000000..44a0b84
--- /dev/null
+++ b/.idea/modules.xml
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/.idea/Leet-Code-prog.iml" filepath="$PROJECT_DIR$/.idea/Leet-Code-prog.iml" />
+    </modules>
+  </component>
+</project>
\ No newline at end of file
diff --git a/.idea/vcs.xml b/.idea/vcs.xml
new file mode 100644
index 0000000..35eb1dd
--- /dev/null
+++ b/.idea/vcs.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="" vcs="Git" />
+  </component>
+</project>
\ No newline at end of file
diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..f738d43
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,10 @@
+cmake_minimum_required(VERSION 4.2)
+project(Leet_Code_prog)
+
+set(CMAKE_CXX_STANDARD 14)
+
+include_directories(Easy/TwoSum)
+
+add_executable(Leet_Code_prog
+        Easy/TwoSum/TwoSum.cpp
+        Easy/TwoSum/TwoSum.h)
diff --git a/Easy/TwoSum/TwoSum.cpp b/Easy/TwoSum/TwoSum.cpp
new file mode 100644
index 0000000..87d9848
--- /dev/null
+++ b/Easy/TwoSum/TwoSum.cpp
@@ -0,0 +1,20 @@
+//
+// Created by bob on 12/04/2026.
+//
+
+#include "TwoSum.h"
+
+class Solution {
+public:
+    vector<int> twoSum(vector<int>& nums, int target) {
+        for (int j = 0; j < nums.size(); j++)
+        {
+            for (int i = 1; i < nums.size(); i++)
+            {
+                if (nums[j]+nums[i] == target)
+                { return {i, j}; }
+            }
+        }
+        return {};
+    }
+};
\ No newline at end of file
diff --git a/Easy/TwoSum/TwoSum.h b/Easy/TwoSum/TwoSum.h
new file mode 100644
index 0000000..1aa3752
--- /dev/null
+++ b/Easy/TwoSum/TwoSum.h
@@ -0,0 +1,16 @@
+//
+// Created by bob on 12/04/2026.
+//
+
+#ifndef LEET_CODE_PROG_TWOSUM_H
+#define LEET_CODE_PROG_TWOSUM_H
+
+
+
+class TwoSum {
+
+};
+
+
+
+#endif //LEET_CODE_PROG_TWOSUM_H
diff --git a/Easy/TwoSum/TwoSum.md b/Easy/TwoSum/TwoSum.md
new file mode 100644
index 0000000..f05e396
--- /dev/null
+++ b/Easy/TwoSum/TwoSum.md
@@ -0,0 +1,39 @@
+# 1. Two Sum
+### Easy
+
+Hint
+Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.
+
+You may assume that each input would have exactly one solution, and you may not use the same element twice.
+
+You can return the answer in any order.
+
+
+
+#### Example 1:
+
+Input: nums = `[2,7,11,15], target = 9`
+
+Output: `[0,1]`
+
+Explanation: Because `nums[0] + nums[1] == 9`, we return `[0, 1]`.
+
+#### Example 2:
+
+Input: nums = [3,2,4], target = 6
+Output: [1,2]
+Example 3:
+
+Input: nums = [3,3], target = 6
+Output: [0,1]
+
+
+### Constraints:
+
+`2 <= nums.length <= 104`
+
+`-109 <= nums[i] <= 109`
+
+`-109 <= target <= 109`
+
+Only one valid answer exists.