lang:cpp vector<int> range(int n) { vector<int> ret(n); for(int i = 0; i < n; ++i) ret[i] = i; return ret; }
春來不似春
vector<int>::iterator it;
for (it = x.begin();it != x.end();it++) doit();
vs.
int i;
for (i = 0;i < n;i++) doit();
...