有序选择L长度排列

http://acm.pku.edu.cn/JudgeOnline/problem?id=3049

参考别人代码写的：

 

#include<stdio.h>

int  L, C;
char list[27], set[27];

void find(int i, int vovel, int ith)
{
	if(ith == L)
	{
		if(vovel)	printf("%s\n", set);
		return ;
	}
	for(; i<=C-L+ith; i++)
	{
		set[ith] = list[i];
		find(i+1, vovel+(set[ith] == 'a' || set[ith] == 'e' || set[ith] == 'i' || set[ith] == 'o' || set[ith] == 'u'), ith+1);
	}
}

int main()
{
	int i, k, arr[123];
	char temp[2];
	while(scanf("%d%d", &L, &C) != EOF)
	{
		for(i='a'; i<='z'; i++)
			arr[i] = 0;
		for(i=0; i<C; i++)
		{
			scanf("%s", temp);
			arr[temp[0]] = 1;
		}
		for(i='a', k=0; i<='z'; i++)
			if(arr[i])
				list[k++] = i;
		set[L] = 0;
		find(0, 0, 0);
	}
	return 0;
}