1032 Sharing (25)

1032 Sharing (25)
To store English words, one method is to use linked lists and store a word letter by letter. To save some space, we may let the words share the same sublist if they share the same suffix. For example, “loading” and “being” are stored as showed in Figure 1.

\ Figure 1

You are supposed to find the starting position of the common suffix (e.g. the position of “i” in Figure 1).

Input Specification:

Each input file contains one test case. For each case, the first line contains two addresses of nodes and a positive N (<= 10^5^), where the two addresses are the addresses of the first nodes of the two words, and N is the total number of nodes. The address of a node is a 5-digit positive integer, and NULL is represented by -1.

Then N lines follow, each describes a node in the format:

Address Data Next

where Address is the position of the node, Data is the letter contained by this node which is an English letter chosen from {a-z, A-Z}, and Next is the position of the next node.

Output Specification:

For each case, simply output the 5-digit starting position of the common suffix. If the two words have no common suffix, output “-1” instead.

Sample Input 1:

11111 22222 9
67890 i 00002
00010 a 12345
00003 g -1
12345 D 67890
00002 n 00003
22222 B 23456
11111 L 00001
23456 e 67890
00001 o 00010
Sample Output 1:

67890
Sample Input 2:

00001 00002 4
00001 a 10001
10001 s -1
00002 a 10002
10002 t -1
Sample Output 2:

-1

解题思路：
用打表的方式，先把遍历一条链，令其flag为true，表示出现过，再遍历另一条，只要有节点的flag为true，就表示已经出现过，即共享节点，立即结束遍历。

#include<cstdio> 
#include<algorithm>
using namespace std;
const int maxn=1e5+10;
struct Node{
    int next;
    char data;
    bool flag;
    Node(){
        flag=false;
    }
}node[maxn];

int main(){
    int s1,s2,n,ad,nex;
    char x;
    scanf("%d%d%d",&s1,&s2,&n);
    for(int i=0;i<n;i++){
        scanf("%d %c %d",&ad,&x,&nex);
        node[ad].data =x;
        node[ad].next =nex;
    }
    for(int i=s1;i !=-1;i=node[i].next ){
        node[i].flag =true;
    }
    int ans=-1;
    for(int i=s2;i!=-1;i=node[i].next){
        if(node[i].flag ==true){
            ans=i;
            break;
        }
    }
    if(ans==-1) printf("-1\n");
    else printf("%05d\n",ans);
    return 0;
}