Two Sum II - Input array is sorted

Author: rahulbordoloi

Leetcode Practice/two_sum_input_arr.cpp

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+// Link - https://leetcode.com/problems/two-sum-ii-input-array-is-sorted
+
+/*
+167. Two Sum II - Input array is sorted
+
+Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number.
+
+The function twoSum should return indices of the two numbers such that they add up to the target, where index1 must be less than index2.
+
+Note:
+
+Your returned answers (both index1 and index2) are not zero-based.
+You may assume that each input would have exactly one solution and you may not use the same element twice.
+ 
+
+Example 1:
+
+Input: numbers = [2,7,11,15], target = 9
+Output: [1,2]
+Explanation: The sum of 2 and 7 is 9. Therefore index1 = 1, index2 = 2.
+Example 2:
+
+Input: numbers = [2,3,4], target = 6
+Output: [1,3]
+Example 3:
+
+Input: numbers = [-1,0], target = -1
+Output: [1,2]
+ 
+
+Constraints:
+
+2 <= nums.length <= 3 * 104
+-1000 <= nums[i] <= 1000
+nums is sorted in increasing order.
+-1000 <= target <= 1000
+*/
+
+class Solution {
+public:
+    vector<int> twoSum(vector<int>& numbers, int target) {
+        
+        int i = 0, j = numbers.size() - 1;
+        while(numbers[i] + numbers[j] != target) {
+            while(numbers[i] + numbers[j] > target) j--;
+            while(numbers[i] + numbers[j] < target) i++;
+        }
+        return {i+1, j+1};
+    }
+};