TwoSum.java

/**
 * Given an array of integers, return indices of the two numbers such that they add up to a specific target.
 *
 * You may assume that each input would have exactly one solution.
 *
 * Example:
 * Given nums = [2, 7, 11, 15], target = 9,
 *  
 * Because nums[0] + nums[1] = 2 + 7 = 9,
 * return [0, 1].
 *
 * UPDATE (2016/2/13):
 * The return format had been changed to zero-based indices. Please read the above updated description carefully.
**/

public class TwoSum {
    public int[] twoSum(int[] nums, int target) {
        int i=0, j=0;
        outer: for(i=0; i<nums.length-1; i++) {
            for(j=i+1; j<nums.length; j++) {
                if(nums[i]+nums[j] == target)
                    break outer;
            }
        }
        return new int[] {i, j};
    }
}