[Codeforces 425A] Sereja and Swaps
Posted evenbao
tags:
篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了[Codeforces 425A] Sereja and Swaps相关的知识,希望对你有一定的参考价值。
[题目链接]
https://codeforces.com/contest/425/problem/A
[算法]
枚举最终序列的左端点和右端点 , 尝试用这段区间中小的数与区间外大的数交换
时间复杂度 : O(N^3logN)
[代码]
#include<bits/stdc++.h> using namespace std; const int MAXN = 210; const int inf = 2e9; int n , k; int a[MAXN],b[MAXN],value[MAXN]; template <typename T> inline void chkmax(T &x,T y) { x = max(x,y); } template <typename T> inline void chkmin(T &x,T y) { x = min(x,y); } template <typename T> inline void read(T &x) { T f = 1; x = 0; char c = getchar(); for (; !isdigit(c); c = getchar()) if (c == ‘-‘) f = -f; for (; isdigit(c); c = getchar()) x = (x << 3) + (x << 1) + c - ‘0‘; x *= f; } int main() { read(n); read(k); for (int i = 1; i <= n; i++) read(value[i]); int ans = -inf; for (int i = 1; i <= n; i++) { for (int j = i; j <= n; j++) { int la = 0 , lb = 0 , cnt = 0; for (int x = 1; x <= n; x++) { if (x >= i && x <= j) { a[++la] = value[x]; cnt += value[x]; } else b[++lb] = value[x]; } sort(a + 1,a + la + 1); sort(b + 1,b + lb + 1,greater<int>()); for (int x = 1; x <= min(la,min(lb,k)); x++) { if (b[x] - a[x] > 0) cnt += b[x] - a[x]; else break; } ans = max(ans,cnt); } } printf("%d ",ans); return 0; }
以上是关于[Codeforces 425A] Sereja and Swaps的主要内容,如果未能解决你的问题,请参考以下文章
CodeForces 380C Sereja and Brackets(扫描线+树状数组)
Sereja and Swaps CodeForces - 426C
CodeForces - 367E:Sereja and Intervals(组合数&&DP)
Codeforces Round #243 (Div. 2)——Sereja and Table