POJ 2001 Shortest Prefixes

传送门：http://poj.org/problem?id=2001

解题思路：

简单的字典树

实现代码：

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <string>
using namespace std;

const int N=27;
struct node{
    int cnt;
    node *childs[N];
    node(){
        cnt=0;
        for(int i=0;i<N;i++)
            childs[i]=NULL;
    }
};

node *root=new node;
node *current,*newnode;

void insert(char *str){
    int n=strlen(str);
    current=root;
    for(int i=0;i<n;i++){
        int m=str[i]-'a';
        if(current->childs[m]!=NULL){
            current=current->childs[m];
            (current->cnt)++;
        }else{
            newnode=new node;
            (newnode->cnt)++;
            current->childs[m]=newnode;
            current=newnode;
        }
    }

}

void search(char *str){
    int n=strlen(str);
    current=root;
    for(int i=0;i<n;i++){
        int m=str[i]-'a';
        if(current->cnt==1){
            printf("
");
            return;
        }else{
            printf("%c",str[i]);
        }
        current=current->childs[m];
    }
    printf("
");
}

int main(){
    char a[5000][300];

    int n=0;
    while(scanf("%s",a[n])!=EOF){
        insert(a[n]);
        n++;
    }
    for(int i=0;i<n;i++){
        printf("%s ",a[i]);
        search(a[i]);
    }

}