/**
* n待查找数组,两数目标之和
* 返回这2个数对应的下标
*/
public int[] towsum(int[] nums, int target) {
Map<Integer,Integer> map = new HashMap<Integer, Integer>();
for (int i = 0; i < nums.length; i++) {
if(map.containsKey(target - nums[i])) {
return new int[] {map.get(target - nums[i]),i};
}
map.put(nums[i], i);
}
return new int[] {-1,-1};
}
复杂度 O(n)