yz467796454的博客

当个板子放着，具体是看了这篇博客：欧拉函数求法与应用欧拉函数用希腊字母φ表示,φ(N)表示N的欧拉函数.对φ(N)的值,我们可以通俗地理解为小于N且与N互质的数的个数(包含1).//直接求解欧拉函数 int euler(int n){ //返回euler(n) int res=n,a=n; for(int i=2;i*i<=a;i++){ ...

图片来源：状压DP初探·总结 位运算是个好东西，希望大家都能会

int extend_gcd( int a, int b, int &x, int &y ){ if (b == 0){ x = 1; y = 0; return a; } else{ int r = extend_gcd( b, a%b, y, x); y -= x*(a/b); return r; }}这个模板 d=exten_gcd( a ...

void permutation(vector<vector<int>>& res, vector<int>& num, int index){ if(index >= num.size()){ res.push_back(num); return; } for(int i = in...

#include <cstdio>#include <cstring>#include <cmath>#include <algorithm>#include <vector>#include <string>#include <map>#include <set>#i

OEIS

namespace fastIO { #define BUF_SIZE 100000 //fread -> read bool IOerror = 0; inline char nc() { static char buf[BUF_SIZE], *p1 = buf + BUF_SIZE, *pend = buf + BUF_SIZE; if(p1 == pend) { ...

中国剩余定理是求解一次同余式组的方法当a互质的时候：#include<iostream>#include<cstdio>#include<climits>#include<cstring>#include<algorithm>using namespace std;int n,m[105],a[105],lcm=...

数论令人头秃，原理就看看别人博客吧：数论之原根#include<cstdio>#include<cstring>#include<cmath>#include<iostream>#include<algorithm>#include <sstream>#include <set>#include