当时打比赛的时候卡在D题了,没有看E.现在看来E还是不难的. 将n个数排序后,其实不排序也是可以的,只是排序能快一半的时间. 枚举前一半能得到多少种和,放到map里面: 然后在后一半数中枚举,然后在map里面查找. #include <bits/stdc++.h> using namespace std; typedef long long LL; ; LL a[maxn], f[maxn], S, ans; int n, m, k; map<int, LL> cnt[maxn];…

Codeforces Round #297 (Div. 2)E. Anya and Cubes Time Limit: 2 Sec  Memory Limit: 512 MBSubmit: xxx  Solved: 2xx 题目连接 http://codeforces.com/contest/525/problem/E Description Anya loves to fold and stick. Today she decided to do just that. Anya has n c…

Codeforces Round #297 (Div. 2)D. Arthur and Walls Time Limit: 2 Sec  Memory Limit: 512 MBSubmit: xxx  Solved: 2xx 题目连接 http://codeforces.com/contest/525/problem/D Description Finally it is a day when Arthur has enough money for buying an apartment. H…

Codeforces Round #297 (Div. 2)C. Ilya and Sticks Time Limit: 2 Sec  Memory Limit: 256 MBSubmit: xxx  Solved: 2xx 题目连接 http://codeforces.com/contest/525/problem/C Description In the evening, after the contest Ilya was bored, and he really felt like ma…

Codeforces Round #297 (Div. 2)B. Pasha and String Time Limit: 2 Sec  Memory Limit: 256 MBSubmit: xxx  Solved: 2xx 题目连接 http://codeforces.com/contest/525/problem/B Description Pasha got a very beautiful string s for his birthday, the string consists o…

Codeforces Round #297 (Div. 2)A. Vitaliy and Pie Time Limit: 2 Sec  Memory Limit: 256 MBSubmit: xxx  Solved: 2xx 题目连接 http://codeforces.com/contest/525/problem/A Description After a hard day Vitaly got very hungry and he wants to eat his favorite pot…

题目传送门 /* 题意:问最少替换'*'为'.',使得'.'连通的都是矩形 BFS:搜索想法很奇妙,先把'.'的入队,然后对于每个'.'八个方向寻找 在2*2的方格里,若只有一个是'*',那么它一定要被替换掉 */ #include <cstdio> #include <iostream> #include <algorithm> #include <cstring> #include <queue> using namespace std; ;…

题目传送门 /* 题意:给n个棍子,组成的矩形面积和最大,每根棍子可以-1 贪心:排序后,相邻的进行比较,若可以读入x[p++],然后两两相乘相加就可以了 */ #include <cstdio> #include <algorithm> #include <cstring> #include <cmath> using namespace std; typedef long long ll; ; const int INF = 0x3f3f3f3f; in…

题目传送门 /* 题意:给出m个位置,每次把[p,len-p+1]内的字符子串反转,输出最后的结果 字符串处理:朴素的方法超时,想到结果要么是反转要么没有反转,所以记录 每个转换的次数,把每次要反转的反转就不超时了:) */ #include <cstdio> #include <algorithm> #include <cstring> using namespace std; ; const int INF = 0x3f3f3f3f; char s[MAXN]; i…

题目传送门 /* 模拟:这就是一道模拟水题,看到标签是贪心,还以为错了呢 题目倒是很长:) */ #include <cstdio> #include <algorithm> #include <iostream> #include <algorithm> #include <cstring> using namespace std; ; const int INF = 0x3f3f3f3f; ]; char s[MAXN]; int main(…