P5151 HKE与他的小朋友

原题链接：https://www.luogu.org/problem/P5151

这题我一开始是从赛后总结里过来的，看到置换乘法啥的，吓死我了。然后瞄了一眼题解，原来倍增也能过，但是比较坑的是，他这个边界压的很恶心，2^31，多了不行，少了也不行，多了估计会int爆掉，少了会WA几个点。我提交了好几次才调整好这个边界，可能是我太菜了。

#include<bits/stdc++.h>
using namespace std;
inline long long read() {
    char ch = getchar(); long long x = 0;short f = 1;
    while(ch < '0' || ch > '9') {
        if(ch == '-') f = -1;
        ch = getchar();
    } while('0' <= ch && ch <= '9') {
        x = x * 10 + ch - '0';
        ch = getchar();
    } return x * f;
}
int f [1000001][33];
inline int query (int x,int k) {
    unsigned long long now = 0;
    for (int i = 31;i >= 0;-- i) {
        if (now + (1 << i) > k) {
            continue ;
        }
        now += 1 << i;
        x = f [x][i];
    }
    return x;
}
int tong [1000005];
int main() {
    int n = read (),k = read ();
    for (int i = 1;i <= n;++ i) {
        f [i][0] = read ();
    }
    //开始倍增
    for (int rk = 1;rk <= 32;++ rk) {
        for (int i = 1;i <= n;++ i) {
            f [i][rk] = f [f [i][rk - 1]][rk - 1];
        }
    } 
    //开始查询
    for (int i = 1;i <= n;++ i) {
        int temp = query (i,k);
        tong [temp] = i;
    }
    for (int i = 1;i <= n;++ i) {
        cout << tong [i];
        if (i != n) {
            cout << " ";
        }
    }
    return 0;
}