三角形的个数

http://acm.tzc.edu.cn/acmhome/problemdetail.do?&method=showdetail&id=3456

include<stdio.h>

include

include

include<string.h>

using namespace std;
int tri[4];
int triN(int n)
{
int number = 0;
for (int i = 1; i <= n / 3; i++)//将三边排序 i是最小的 j 是第二 m-j是最大的
{
int m = n - i;
for (int j = i; j <= m / 2; j++)//第二条边一定会大于等于第三条边否则会出现 4 5 5 5 4 5的情况
{
if(m-ji&&ij)continue;
if (m - j - j < i)
number++;
}
}
return number;
}
int main()
{
int n;
while(~scanf("%d",&n))
{
printf("%d\n",triN(n));
}
return 0;
}