2171.cpp

这是哈尔滨工业大学acmOJ的源代码

/*  This Code is Submitted by wywcgs for Problem 2171 on 2006-03-13 at 12:24:07 */ 
#include <cstdio>
#include <cstring>

const int MAX = 102400;

int main()
{
	char word[MAX];
	int i, t, T, n;
	
	scanf("%d", &T);
	for(t = 0; t < T; t++) {
		scanf("%d %s", &n, word);
		int len = strlen(word), b = 0, e = len-1;
		for(i = 0; i < n && len >= 4; i++) {
			len -= len / 4;
			if(i & 1) e = b + len - 1;
			else b = e - len + 1;
		}
		for(i = b; i <= e; i++) putchar(word[i]);
		putchar('\n');
	}
	
	return 0;
}