工具网址

Latex在线编辑 https://zybuluo.com/mdeditor

Latex数学公式 https://www.luogu.com.cn/blog/IowaBattleship/latex-gong-shi-tai-quan

图论工具 https://csacademy.com/app/graph_editor/

Atcoder https://kenkoooo.com/atcoder/#/table/luogu_bot1

数学(质数)https://www.haomeili.net/

快读:

#include<bits/stdc++.h>
#define INF 0x3f3f3f3f
using namespace std;
namespace FastIO {
    char buf[1<<21], *p1=buf, *p2=buf;
    inline int getch (void) {
        return p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<21,stdin),p1==p2)?EOF:*p1++;
    }
    inline int read (void) {
        int x = 0, f = 1, ch = getch();
        while(!isdigit(ch)) {
            if(ch == '-') f = -f;
            ch = getch();
        }
        while(isdigit(ch)) {
            x = x * 10 + ch - '0';
            ch = getch();
        }
        return x * f;
    }
    char buf2[1<<21], buf3[25];
    int tp_l, buf2_l=-1;
    inline void flush (void) {
        fwrite (buf2, 1, buf2_l+1, stdout), buf2_l=-1;
    }
    inline void print (int x, char ch=10) {
        if(buf2_l>(1<<20)) flush();
        if(x<0) buf2[++buf2_l]='-', x=-x;
        do buf3[++tp_l]=x%10+48;
        while(x/=10);
        do buf2[++buf2_l]=buf3[tp_l];
        while(--tp_l);
        buf2[++buf2_l] = ch;
    }
}
using FastIO::read;
using FastIO::print;
int main() {
    FastIO::flush();
    return 0;
}