PAT 1032 Sharing

http://pat.zju.edu.cn/contests/pat-practise/1032

好吧，注意有可能存在空串，别的就没什么了，代码写的比较烂，有好多不必要的重复。

#include <stdio.h>
struct Node{
    int next_num;
    char ch;
};

struct Node nodes[100002];
int main()
{
    int head1,head2,node_num;
    scanf("%d%d%d",&head1,&head2,&node_num);
    int i;
    for(i=0;i<node_num;i++) {
        int cur_node,next_num;
        char cur_ch;
        scanf("%d %c %d",&cur_node,&cur_ch,&next_num);
        nodes[cur_node].ch=cur_ch;
        nodes[cur_node].next_num=next_num;
    }

    if(head1==-1||head2==-1){
        printf("-1\n");
        return 0;
    }
    int len1=0,len2=0;

    int nu=head1;
    while(nodes[nu].next_num!=-1) {
        nu=nodes[nu].next_num;
        len1++;
    }
    nu=head2;
    while(nodes[nu].next_num!=-1) {
        nu=nodes[nu].next_num;
        len2++;
    }

    int max=-1;
    if(len1!=len2) {
        if(len1>len2) {
            max=len1;
        } else {
            max=len2;
        }
    }

    if(max==len1) {
        int dif=len1-len2;
        while(dif--) {
            head1=nodes[head1].next_num;
        }
    } else {
        int dif=len2-len1;
        while(dif--) {
            head2=nodes[head2].next_num;
        }
    }
    //now aligned

    while(head1!=-1&&head2!=-1) {
        if(head1==head2) {
            printf("%05d\n",head1);
            return 0;
        }
        head1=nodes[head1].next_num;
        head2=nodes[head2].next_num;
    }
    printf("-1\n");
    return 0;
}