位压缩，用两个unsigned long long型（共128位）表示一个人听到的树编号，排序，统计互异的元素个数
#include <stdio.h>
#include <math.h>
unsigned long long a[100] = {0};
unsigned long long b[100] = {0};
void bubble_sort(int n){
	for(int i = 0; i < n; i++){
		for(int j = n-1; j > i; j--){
			if(b[j] < b[j-1] || (b[j] == b[j-1] && a[j] < a[j-1])){
				unsigned long long tmp1 = b[j];
				b[j] = b[j-1];
				b[j-1] = tmp1;
				unsigned long long tmp2 = a[j];
				a[j] = a[j-1];
				a[j-1] = tmp2;
			}
		}
	}
}
int main(){
	int p, t;
	int i, k;  //i是人编号，k是树编号
	scanf("%d%d", &p, &t);
	while(scanf("%d%d", &i, &k) != EOF){
		if(k <= 50)  //因为有重复说的，所以这里只能用|=而不能用+=
			a[i-1] |= (unsigned long long)pow(2, k-1);
		else
			b[i-1] |= (unsigned long long)pow(2, k-50-1);
	}
	bubble_sort(p);
	int cnt = 1;
	for(int i = 1; i < p; i++)
		if(a[i] != a[i-1] || b[i] != b[i-1])
			cnt++;
	printf("%d\n", cnt);
	return 0;
}

• Re:0ms AC，附代码 (9) bleedkaga 2011-10-26 11:57:40