libreOJ模板并查集（输入挂，取模与find优化）

Posted 2021-01-06 suut

1.了解了各种输入挂性orz，找到了一个合适的 

2.find用while写能快一倍，并且能被数据卡掉

3.取模只能快十几毫秒，但也能被数据卡掉

取模find双优化是1997mm过的 

再加一个性价比较高的输入挂是438mm  23333

#include <cstdio>
#include <cmath>
#include <complex>
#include <algorithm>
#include <iostream>
#include<string.h>
#include<vector>
#include<ctime>
#define rep(i,t,n)  for(int i =(t);i<=(n);++i)
#define per(i,n,t)  for(int i =(n);i>=(t);--i)
#define mmm(a,b) memset(a,b,sizeof(a))
typedef long long ll;
using namespace std;
#define N 2333333
const ll M= 998244353;
const int maxn = 4e6 + 5;
int f[maxn];
using namespace std;

template<typename T>inline void add_(T &A, int B, ll MOD = M) { A += B; (A >= MOD) && (A -= MOD); }
template<typename T>inline void mul_(T &A, ll B, ll MOD = M) { A = (A*B) % MOD; }
namespace IO
{
    const int MAXL = 1 << 15;
    char buf[MAXL], *S, *T, ch;

    inline char Getch()
    {
        if (S == T) T = (S = buf) + fread(buf, 1, MAXL, stdin);
        return S == T ? EOF : *S++;
    }

    inline void Read(int &x)
    {
        x = 0;
        while (!isdigit(ch = Getch()));
        do { x = x * 10 + (ch ^ ‘0‘); } while (isdigit(ch = Getch()));
    }
}
using namespace IO;

int  find(int x) {
    while (f[x] ^ x)x = f[x] = f[f[x]]; return x;
}
void un(int x, int y) {
    int xx = find(x), yy = find(y);
    if(xx^yy)f[xx] = yy;
}
int main() {
    int n, m;
    cin >> n >> m;
    rep(i, 1, n)f[i] = i;
    int op, a,  b;
    ll ans = 0;
    rep(i, 1, m) {
        Read(op); Read(a); Read(b);
        if(!op)un(a, b);
        else {
            add_(ans, ans + (find(a) == find(b)));    
        }
    }
    cout << ans << endl;
    cin >> n;
}