Problem Statement

Problem Sources: LeetCode
Input: variable A: Array of Number and variable B: Number
Process: Return two Index of Variable A that if those two value of the Index summed up it should be equal to the variable B. Business Rule: Can only use one same element or element index

Test Cases

Input: nums = [2,7,11,15], target = 9
Output: [0,1]
reasoning: nums[0] + nums [1] = 2+7 = 9

Solution

below solution still has O(N^2) performance

function twoSum(nums: number[], target: number): number[] {
    let output: Array<number> = [];
    let loopProcess: boolean = true;
    for(var x = 0;x<nums.length && loopProcess == true;x++){
        for(var y = 0; y<nums.length && loopProcess;y++){
            if(y !== x){
                if(nums[x]+nums[y] == target){
                    output.push(x);
                    output.push(y);
                    loopProcess = false;
                }
            }
        }
    }
    return output;
};