【置换群】 HDOJ 1439 && POJ 1026 Cipher

#include <iostream>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <bitset>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <climits>
#include <cstdlib>
#include <cmath>
#include <time.h>
#define maxn 100005
#define maxm 40005
#define eps 1e-10
#define mod 1000000007
#define INF 999999999
#define lowbit(x) (x&(-x))
#define mp mark_pair
#define ls o<<1
#define rs o<<1 | 1
#define lson o<<1, L, mid
#define rson o<<1 | 1, mid+1, R
typedef long long LL;
//typedef int LL;
using namespace std;
LL powmod(LL a, LL b){LL res=1,base=a;while(b){if(b%2)res=res*base%mod;base=base*base%mod;b/=2;}return res;}
void scanf(int &__x){__x=0;char __ch=getchar();while(__ch==' '||__ch=='\n')__ch=getchar();while(__ch>='0'&&__ch<='9')__x=__x*10+__ch-'0',__ch = getchar();}
LL gcd(LL _a, LL _b){if(!_b) return _a;else return gcd(_b, _a%_b);}
// head

int change[maxn], next[maxn], vis[maxn];
int c[maxn], f[maxn];
char s[maxn], t[maxn];
int n, m, k;
void work(void)
{
int
now, cnt, len;
memset(vis, 0, sizeof vis);
for(int i = 1; i <= n; i++) if(!vis[i]) {
now = i, cnt = 1, f[now] = i;
while(change[now] != i) vis[now] = 1, now = change[now], cnt++, f[now] = i;
vis[now] = 1, c[i] = cnt;
}
while(scanf("%d", &k), k != 0) {
for(int i = 1; i <= n; i++) next[i] = i;
for(int i = 1; i <= n; i++) {
int t = k % c[f[i]];
while(t--) next[i] = change[next[i]];
}
getchar(), gets(s+1);
len = strlen(s+1);
for(int i = len+1; i <= n; i++) s[i] = ' ';
for(int i = 1; i <= n; i++) t[next[i]] = s[i];
t[n+1] = '\0';
puts(t+1);
}
}
int main(void)
{
while(scanf("%d", &n), n != 0) {
for(int i = 1; i <= n; i++) scanf("%d", &change[i]);
work();
puts("");
}
return 0;
}