Example:
Given nums = [
2,
7,
11,
15], target =
9,
Because nums[
0] + nums[
1] =
2 +
7 =
9,
return [
0,
1].
方案：hash查找
#include<iostream>
#include<vector>
#include<unordered_map>
vector<int> twosum(
vector<int>& v,
int target)
{
unordered_map<int,int> m;
vector<int> v1;
int val;
for(
int i=
0;i<v.size();i++)
{
m[v[i]]=i;
}
for(
int j=
0;j<v.size();j++)
{
val=target-v[j];
if(m.count(val) && m[val]!=j)
{
v1.push_back(j);
v1.push_back(m[val]);
break;
}
}
return v1;
}
int main()
{
vector<int> v={
2,
7,
11,
15};
vector<int> vv=twosum(v,
9);
for(
auto iter:vv)
cout<<iter<<
" ";
}
