leetcode 1.Two sum

leetcode 1.Two sum

Difficulty:Easy

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, and you may not use the same element twice.

Example:

Given nums = [2, 7, 11, 15], target = 9,

Because nums[0] + nums[1] = 2 + 7 = 9,

return [0, 1].

//先Map，再查找对应下标
class Solution {
public:
vector<int> twoSum(vector<int>& nums, int target) {
bool vis[nums.size()+1]={false};
for(int i=0;i<nums.size();i++){
Hash[nums[i]]=i;
}
vector<int> result;
for(int i=0;i<nums.size();i++){
int rs=target-nums[i];
vis[i]=true;
if(Hash.find(rs)!=Hash.end()&&Hash[rs]!=i){
result.push_back(i);
result.push_back(Hash[rs]);
return result;
}
}
return result;
}
};