codeforces——Little Pony and Expected Maximum

所以最后的结果=sum((k/m)^n - ((k-1)/m)^n) (1 =k =m) 不要这样求（k^n/m^n）数据可能会很大！ #include iostream #include cstdio #include cmath using namespace std; int main(){ int n, m; while(cin m n){ double sum, cur=pow(1.0/m, n), nt; sum=cur; for(int i=2; i ++i){ nt=pow(i*1.0/m, n); sum+=(nt-cur)*i; cur=nt; printf("%.12lf\n", sum); return 0; }
codeforces Educational Codeforces Round 49 (Rated for Div. 2) C题 刚开始拿到这题很懵逼，知道了别人的思路之后开始写，但是还是遇到很多坑，要求求P2/S最大。p=a b。就是求（a2+ b2 +2ab)/ab最大，也就是a/b +b/a最大。那么题意就很明显了。
Educational Codeforces Round 98 (Rated for Div. 2)B-Toy Blocks You are asked to watch your nephew who likes to play with toy blocks in a strange way. He has n boxes and the i-th box has ai blocks. His game consists of two steps: he chooses an arbitrary box i; he tries to move all blocks from the i-th box to other boxes.