顺便也看看我的代码吧！也是c++就ac换g++就wa！感觉我的数组没问题啊!
#include<stdio.h>
#include<stdlib.h>
#include<math.h>
struct point {
	int x,y;
};
struct point P[1005];
struct point result[1005];
int n,cur;
double dis(point a,point b)
{
	double temp;
	temp=(a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y);
	temp = sqrt(temp);
	return temp;
}
int mul(point a,point b,point c)
{
	return (b.x-a.x)*(c.y-a.y)-(b.y-a.y)*(c.x-a.x);
}
int cmp(const void *a,const void *b)
{
	struct point *aa = (struct point *)a;
	struct point *bb = (struct point *)b;
	int t;
	t = mul(P[0],*aa,*bb);
	if (t < 0)
		return 1;
	else if (t == 0&&(dis(P[0],*aa)<dis(P[0],*bb)))
	return 1;
	else return -1;
}
void tubao(int n)
{
	int i;
	result[0] = P[0];
	result[1] = P[1];
	result[2] = P[2];
	cur = 2;
	for (i = 3;i <= n;i++)
	{
		while (mul(result[cur-1],result[cur],P[i]) < 0 && cur >= 2)
		{
			cur--;
		}
		cur++;
		result[cur] = P[i];
	}
}
int main()
{
	int i,l,px,py,p;
	struct point temp;
	double sum;
	while (scanf ("%d%d",&n,&l)!= EOF)
	{
		for (i = 0; i< n;i++)
		{
			scanf ("%d%d",&P[i].x,&P[i].y);
			if (i == 0||px<P[i].x)
			{
				px = P[i].x;
				py = P[i].y;
				p = i;
			}
			else if (px == P[i].x&&py<P[i].y)
			{
				px = P[i].x;
				py = P[i].y;
				p = i;
			}
		}
		temp = P[0];
		P[0] = P[p];
		P[p] = temp;
		qsort(P+1,n-1,sizeof(P[0]),cmp);
		P[n] = P[0];
		tubao(n);
		sum = 0;
		for (i = 0; i< cur;i++)
			sum+=dis(result[i],result[i+1]);
		sum+=2*3.1415926*l;
		printf ("%.0lf\n",sum);
	}
	return 0;
}

• 把printf 里面的 %lf 改成 %f G++就行了 G++的浮点型需要%f输出，%lf就是WA (0) city 2010-05-01 17:17:18
  • 上面说地太对了，本人因为这个错了一版。。。。 (0) 541780774 2011-02-24 19:35:55
  • 啊，竟然是这个问题！ (10) wzhgba 2011-05-12 13:10:21
  • 我也是这个问题……以后交程序要C++ G++各交一遍…… (0) bg95 2011-09-17 16:50:17