您的程序没有结果，我稍微修改了一下可以得到结果。非常感谢您的帮助！
{
    int a[]={1,2,3,4,5,4,3,2,1,2,3,4,5,4,3,2,1,2,3,4,5,4,3};
    int i;
    int count = 0;
    for(i=0; i<=19; i++)
    {
        if(count != 2)
        {
            if (a[i]<a[i+1]&&a[i+1]>a[i+2])
            {
                printf("%d %d\n", i+1, a[i+1]);
                count++;   
            }
        }
        else break;
    }            
}