1. Two Sum

class Solution {
    public int[] twoSum(int[] nums, int target) {
        int arr[] = new int[2];
        for(int i = 0 ; i < nums.length ; i++){
            for(int j = i+1 ; j < nums.length ; j++){
                if(nums[i] + nums[j] == target){
                    arr[0] = i;
                    arr[1] = j;
                }
            }
        }
        return arr;
    }
}

1. Best Time to Buy and Sell Stock

1. Merge Sorted Array

class Solution {
    public void merge(int[] nums1, int m, int[] nums2, int n) {
        System.arraycopy(nums2 , 0 , nums1 , m , n);
        Arrays.sort(nums1);
    }
}

class Solution {
    public void merge(int[] nums1, int m, int[] nums2, int n) {
        for(int j = 0 , i = m ;  j < n ; j++){
            nums1[i] = nums2[j];
            i++;
        }
        Arrays.sort(nums1);
    }
}