找出数组中和为S的一对组合，找出一组就行

Answer 1

考察点：数组

 

public int[] twoSum(int[] nums, int target) {
        HashMap<Integer, Integer> map =new HashMap<Integer, Integer>();
        int[] a = new int[2];
        map.put(nums[0], 0);
        for (int i = 1; i < nums.length;i++) {
            if (map.containsKey(target - nums[i])) {
                a[0] = map.get(target -nums[i]);
                a[1] = i;
                return a;
            } else {
                map.put(nums[i], i);
            }
        }
        return a;
}