#include <cstdio>using namespace std;typedef long long LL;const int maxn = 50;int a[maxn];int main(){int n,p;char op[20];scanf("%d%d",&n,&p);for(int i = 0; i < n;++i){scanf("%s",op);a[i] = op[4] != ‘\0‘;}LL cnt = 0,bcnt = 0;for(int i = n - 1;i >= 0 ;--i){if(a[i]){cnt = cnt * 2 + 1;++bcnt;}else{cnt = cnt * 2;}}printf("%I64d\n",cnt*p - bcnt * (p / 2));return 0;}
[2016-03-26][codeforces][632][A][Grandma Laura and Apples]
原文:http://www.cnblogs.com/qhy285571052/p/17be49109610a1d24ddad5c171a5287a.html