Question
Analysis
Answer
class Solution{
public:
vector <vector <int>> threeSum (vector <int> & num)
{
vector <vector <int>> result;
if (num.size()<3) return result;
int ans=0;
sort (num.begin(),num.end());
for (int i=0;i<num.size()-2;++i)
{
if (i>0 && num[i]==num[i-1])
continue;
int j=i+1;
int k=num.size()-1;
while(j<k)
{
ans=num[i]+num[j]+num[k];
if (ans==0)
{
result.push_back({num[i],num[j],num[k]});
++j;
while (j<num.size() && num[j]==num[j-1])
++j;
--k;
while(k>=0 &&num[k]==num[k+1])
--k;
}
else if (ans>0)
--k;
else
++j;
}
}
return result;
}
};
参考：https://www.kancloud.cn/kancloud/data-structure-and-algorithm-notes/72956
