PCK本戦2問目：後になって書いてみた編

pck2012_2.c

#include <stdio.h>

#define LIMIT	(10000)

int main(void)
{
	int n;
	int mem[2][10000];
	int ct;
	int under_line;
	int dl;
	int i, j;
	int index;
	
	while (scanf("%d", &n), n){
		for (i = 0; i < n; i++){
			scanf("%d", &mem[0][i]);
		}
		
		under_line = n;
		for (ct = 0; ct < LIMIT; ct++){
			for (i = 0; i < under_line && mem[ct & 1][i] == i + 1; i++);
			if (i == under_line) break;
			
			dl = index = 0;
			for (i = 0; i < under_line; i++){
				dl -= !(--mem[ct & 1][i]);
				if (mem[ct & 1][i]) mem[!(ct & 1)][index++] = mem[ct & 1][i];
			}
			mem[!(ct & 1)][index] = under_line;
			under_line = under_line + 1 + dl;
		}
		printf("%d\n", ct != LIMIT ? ct : -1);
	}
	
	return (0);
}