郑轻oj 1159: 最大的两个数（指针专题）_1159: 最大的两个数(指针专题)

 比较耗时的做法：

#include <stdio.h>
 
void LargestTow(int a[],int n,int *pfirst,int *psecond)
{
    int max = 0;
    *pfirst = a[0];;
    for (int i = 1; i < n; ++i)
    {
        if (a[i] > *pfirst)
        {
            *pfirst = a[i];
            max = i;
        }
    }
    for (int i = max; i < n - 1; ++i)
        a[i] = a[i + 1];
    *psecond = a[0];
    for (int i = 0; i < n - 1; ++i)
        if (a[i] > *psecond) *psecond = a[i];
}
 
int main()
{
    int n, a[1010], x, y;
    scanf("%d", &n);
    for (int i = 0; i < n; ++i) scanf("%d", &a[i]);
    LargestTow(a, n, &x, &y);
    printf("%d %d", x, y);
    return 0;
}

省时间是做法：

#include <iostream>
#include <algorithm>
using namespace std;
 
void LargestTow(int a[],int n,int *pfirst,int *psecond)
{
	*pfirst = a[0], *psecond = a[1];
	if (*psecond > *pfirst) swap(*psecond, *pfirst);
	for (int i = 1; i < n; ++i)
	{
		if (a[i] > *pfirst) 
		{
			*psecond = *pfirst;
			*pfirst = a[i];
		}
		else if (a[i] > *psecond) *psecond = a[i];
	}
}
 
int main()
{
	int n, a[1010], first = 0, second = 0;
	cin >> n;
	for (int i = 0; i < n; ++i) cin >> a[i];
	LargestTow(a, n, &first, &second);
	printf("%d %d", first, second);
	return 0;
}