杭电1200

#include <iostream>#include <cstdio>#include <cstring>using namespace std;int main(){char all[210];char Zhuanhuan[110][110];int N;int i,j,k,len;while(~scanf("%d",&N)&&N){scanf("%s",all);i=0;k=0;len=strlen(all);for(i=0;i<len;i++){if(i/N%2==0){Zhuanhuan[i/N][k]=all[i];k++;}else {k--;Zhuanhuan[i/N][k]=all[i];}}for(i=0;i<N;i++){for(j=0;j<len/N;j++){printf("%c",Zhuanhuan[j][i]);}}printf("\n");}return 0;}