题目描述 Farmer John has arranged his N (1 ≤ N ≤ 5,000) cows in a row and many of them are facing forward, like good cows. Some of them are facing backward, though, and he needs them all to face forward to make his life perfect. Fortunately, FJ recently…
题目传送门 题目描述 Farmer John has arranged his N (1 ≤ N ≤ 5,000) cows in a row and many of them are facing forward, like good cows. Some of them are facing backward, though, and he needs them all to face forward to make his life perfect. Fortunately, FJ rec…
发现选定一个长度后,怎么翻转是固定的. 那我们直接选定一个长度去操作就行. 优化操作过程 类似于堆里打持久化标记一样的感觉. [USACO07MAR]Face The Right Way G // Problem: P2882 [USACO07MAR]Face The Right Way G // Contest: Luogu // URL: https://www.luogu.com.cn/problem/P2882 // Memory Limit: 125 MB // Time Limit:…
P2882 [USACO07MAR]面对正确的方式Face The Right Way $n<=5000$?枚举翻转长度,顺序模拟就ok了 对于每次翻转,我们可以利用差分的思想,再搞搞前缀和. (输出反了还交,真菜) #include<iostream> #include<cstdio> #include<cstring> using namespace std; #define N 10010 int n,a[N],s[N],p[N],ans,mnd=1e9;…
题目链接 https://www.luogu.com.cn/problem/P2882 分析 这个题来看的话好像有点难下手,不如再去读一遍题 N遍,发现一句话很重要Each time the machine is used, it reverses the facing direction of a contiguous group of K cows in the line,就是说只能翻转固定的长度区间,那这样是不是就可以枚举区间了?枚举一层区间,再枚举每次起点,最后加上区间修改,时间复杂度\…
题目描述 Farmer John has arranged his N (1 ≤ N ≤ 5,000) cows in a row and many of them are facing forward, like good cows. Some of them are facing backward, though, and he needs them all to face forward to make his life perfect. Fortunately, FJ recently…
