见过无数次了,终于写了一次,一个数组都没用。
vector<vector<int> > generate(int numRows) {
vector<int> oneresult;
vector<vector<int> > ret;
if(numRows==0)
return ret;
oneresult.push_back(1);
ret.push_back(oneresult);
oneresult.clear();
int len;
for (int i=2;i<=numRows;i++)
{
oneresult.push_back(1);
len = ret.size();
for (int j=0;j<ret[len-1].size()-1;j++)
oneresult.push_back(ret[len-1][j]+ret[len-1][j+1]);
oneresult.push_back(1);
ret.push_back(oneresult);
oneresult.clear();
}
return ret;
}