记一笔、三三两两

全排列（next_permutation)代码如下：#include <bits/stdc++.h>using namespace std;#define PI 2*acos(0.0)int main (){ int t, cnt = 1; scanf("%d", &t); while(t--) { int k, n, sum = 0;

生成树 代码如下：#include <bits/stdc++.h>using namespace std;int mat[2][110][110];const int inf = 1e9;int vis[110], dis[110], n;int dij(int dex){ memset(dis, 0x3f3f3f, sizeof(dis)); memset(vis, 0

求因子个数 代码如下： #include <bits/stdc++.h> using namespace std; int prime[1000010]; long long a[100010]; int main () { int sum = 0; for(int i = 2; i <= 1000000; i++)

概率 假设期望时间为p p=∑n−1i=0(xi<0?xi+p:xi)np = \dfrac{\sum_{i = 0}^{n-1}(x_i<0 ? x_i+p:x_i)}{n}代码如下：#include <bits/stdc++.h>using namespace std;int main (){ int t, cnt = 1; scanf("%d", &t);

割边(输出要排序，贼鸡儿坑)代码如下：#include <bits/stdc++.h>using namespace std;vector<int> k[10010];int num[10010], vis[10010], low[10010];pair<int, int>edge[10010];int __index;void Init(int n)//初始化{ __index =

简单几何代码如下：#include <bits/stdc++.h>using namespace std;#define PI acos(-1.0)int main (){ int t, cnt = 1; scanf("%d", &t); while(t--) { double R, r, n; scanf("%lf %lf", &R,

区间DP代码如下：#include <bits/stdc++.h>using namespace std;long long dp[110][110];int main (){// freopen("E:\\1.in", "r", stdin);// freopen("E:\\1.out", "w", stdout); int t, cnt = 1; scanf("

位运算模拟代码如下：#include <bits/stdc++.h>using namespace std;int main (){ int t, cnt = 1; scanf("%d", &t); while(t--) { int n; scanf("%d", &n); int i = 0; int

高精度乘法代码如下：#include <bits/stdc++.h>using namespace std;int b[50010], a[50010];int c[10010];void Print(int n){ memset(c, 0, sizeof(c)); int m = 1; c[0] = 1; for(int i = 0; i < n; i++)

斯特林公式代码如下：#include <bits/stdc++.h>using namespace std;#define PI 2*acos(0)int main (){ int t, cnt = 1; scanf("%d", &t); while(t--) { int n, k; scanf("%d %d", &n, &k);