求助求助 新手第一次发帖 请多指教啊 点9WA了??

#include<iostream>
using namespace std;
struct person
{
	int chinese;
	int english;
	int math;
	int num;
	int sum;
};
int main()
{
	person a[301];
	int n;
	cin >> n;
	for (int i = 1; i <= n; ++i)
	{
		a[i].num = i;
		cin >> a[i].chinese;
		cin >> a[i].math;
		cin >> a[i].english;
		a[i].sum = a[i].chinese + a[i].math + a[i].english;
	}//输入
	person b;
	for (int j = 1; j <= n; ++j)
		for (int i = 1; i <= n; ++i)
			if (a[i].sum < a[i + 1].sum)
			{
				b = a[i];
				a[i] = a[i + 1];
				a[i + 1] = b;
			}
	for (int j = 1; j <= n; ++j)
		for (int i = 1; i <= n; ++i)
			if (a[i].sum == a[i + 1].sum)
			{
				if (a[i].chinese < a[i + 1].chinese)
				{
					b = a[i];
					a[i] = a[i + 1];
					a[i + 1] = b;
				}
			}

	for (int j = 1; j <= n; ++j)
		for (int i = 1; i <= n; ++i)
			if (a[i].sum == a[i + 1].sum && a[i].chinese == a[i + 1].chinese)
				if (a[i].num > a[i].num)
				{
					b = a[i];
					a[i] = a[i + 1];
					a[i + 1] = b;
				}
	for (int i = 1; i <= 5; ++i)
		cout << a[i].num << " " << a[i].sum << endl;
	return 0;
}