/*构造哈夫曼树的n-1个非叶节点*/
    for (i = 0; i < n - 1; i++)
    {
        m1 = m2 = MaxValue;
        x1 = x2 = 0;
        for (j = 0; j < n - 1; j++)
        {
            if (haffTree[j].weight < m1&&haffTree[j].flag == 0)         
            {
                m2 = m1;                                                    //此处赋值
                x2 = x1;
                m1 = haffTree[j].weight;
                x1 = j;
            }
            else if (haffTree[j].weight < m2&&haffTree[j].flag == 0)            //那么此处不就是和上面的判断一样吗这里的m2等于上面的m1，最后怎么的出两个最小的权值呢？
            {
                m2 = haffTree[j].weight;
                x2 = j;
            }
        }

顶一下

用debug跟踪一下这个程序

#include <stdio.h>

int main()
{
    int sa[] = { 5, 7, 1, 3, 6, 2, 4, 2, 9, 7};
    int size = sizeof(sa) / sizeof(sa[0]);
    int x1, x2, m1, m2;

    m1 = m2 = 100;
    x1 = x2 = 0;
    for (int i = 0;i < size;i++)
    {
        if (sa[i] < m1)
        {
            m2 = m1;
            x2 = x1;

            m1 = sa[i];
            x1 = i;
        }
        else if (sa[i] < m2)
        {
            m2 = sa[i];
            x2 = i;
        }
    }

    printf("x1 = %d, m1 = %d\n", x1, m1);
    printf("x2 = %d, m2 = %d\n", x2, m2);
}