【POJ】1026.Cipher

#include <iostream>
#include <cstdio>
#include <vector>
#include <set>
#include <cstring>
#include <ctime>
#include <map>
#include <algorithm>
#include <cmath>
#define MAXN 100005
#define eps 1e-8
//#define ivorysi
#define pii pair<int,int>
#define mp make_pair
#define fi first
#define se second
using namespace std;
typedef long long int64;
typedef double db;

int N,a[MAXN],L,ans[MAXN],t[MAXN],K,tmp[MAXN];
char str[MAXN],s[MAXN];
void mul(int *c,int *d) {
    for(int i = 1 ; i <= N ; ++i) tmp[i] = c[d[i]];
    for(int i = 1 ; i <= N ; ++i) c[i] = tmp[i];
}
void fpow(int c) {
    for(int i = 1 ; i <= N ; ++i) t[i] = a[i];
    for(int i = 1 ; i <= N ; ++i) ans[i] = i;
    while(c) {
        if(c & 1) mul(ans,t);
        mul(t,t);
        c >>= 1;
    }
}
int main() {
#ifdef ivorysi
    freopen("f1.in","r",stdin);
#endif
    while(scanf("%d",&N) != EOF && N) {
        for(int i = 1 ; i <= N ; ++i) {
            scanf("%d",&a[i]);
        }
        while(scanf("%d",&K) != EOF && K){
            for(int i = 1 ; i <= N ; ++i) str[i] = ‘ ‘;
            getchar();
            gets(str + 1);
            L = strlen(str + 1);
            for(int i = 1 ; i <= N ; ++i) {
                if(str[i] == 0) str[i] = ‘ ‘;
            }
            fpow(K);
            for(int i = 1 ; i <= N ; ++i) {
                s[ans[i]] = str[i];
            }
            for(int i = 1 ; i <= N ; ++i) putchar(s[i]);
            putchar(‘\n‘);
        }
        putchar(‘\n‘);
    }
    return 0;
}