图论trainning-part-1 B. A Walk Through the Forest
B. A Walk Through the Forest
64-bit integer IO format: %I64d Java class name: Main
The forest is beautiful, and Jimmy wants to take a different route everyday. He also wants to get home before dark, so he always takes a path to make progress towards his house. He considers taking a path from A to B to be progress if there exists a route from B to his home that is shorter than any possible route from A. Calculate how many different routes through the forest Jimmy might take.
Input
Output
Sample Input
5 6
1 3 2
1 4 2
3 4 3
1 5 12
4 2 34
5 2 24
7 8
1 3 1
1 4 1
3 7 1
7 4 1
7 5 1
6 7 1
5 2 1
6 2 1
0
Sample Output
2
4 解题:最短距离+记忆化搜索,找出1到终点2上的所有点,假设A,B两点,如果统计d[A] > D[B]这种路径的条数。
#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <climits>
#include <vector>
#include <queue>
#include <cstdlib>
#include <string>
#include <set>
#define LL long long
#define INF 0x3f3f3f
using namespace std;
const int maxn = ;
int mp[maxn][maxn],d[maxn],p[maxn];
int n,m;
bool vis[maxn];
void dij(int src){
int i,j,temp,index;
for(i = ; i <= n; i++)
d[i] = INF;
d[src] = ;
memset(vis,false,sizeof(vis));
for(i = ; i < n; i++){
temp = INF;
for(j = ; j <= n; j++)
if(!vis[j] && d[j] < temp) temp = d[index = j];
vis[index] = true;
for(j = ; j <= n; j++)
if(!vis[j] && d[j] > d[index]+mp[index][j])
d[j] = d[index] + mp[index][j];
}
}
int dfs(int s){
if(p[s]) return p[s];
if(s == ) return ;
int i,sum = ;
for(i = ; i <= n; i++){
if(mp[s][i] < INF && d[s] > d[i]) sum += dfs(i);
}
p[s]+= sum;
return p[s];
}
int main(){
int i,j,u,v,w;
while(scanf("%d",&n),n){
scanf("%d",&m);
for(i = ; i <= n; i++)
for(j = ; j <= n; j++)
mp[i][j] = INF;
for(i = ; i < m; i++){
scanf("%d%d%d",&u,&v,&w);
mp[u][v] = mp[v][u] = w;
}
dij();
memset(p,,sizeof(p));
printf("%d\n",dfs());
}
return ;
}
图论trainning-part-1 B. A Walk Through the Forest的更多相关文章
- A Walk Through the Forest[HDU1142]
A Walk Through the Forest Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Jav ...
- hduoj----1142A Walk Through the Forest(记忆化搜索+最短路)
A Walk Through the Forest Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Jav ...
- HDU 1142 A Walk Through the Forest (记忆化搜索 最短路)
A Walk Through the Forest Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Jav ...
- HDU 1142 A Walk Through the Forest (求最短路条数)
A Walk Through the Forest 题目链接: http://acm.hdu.edu.cn/showproblem.php?pid=1142 Description Jimmy exp ...
- UVa 10917 A Walk Through the Forest
A Walk Through the Forest Time Limit:1000MS Memory Limit:65536K Total Submit:48 Accepted:15 Descrip ...
- hdu_A Walk Through the Forest ——迪杰特斯拉+dfs
A Walk Through the Forest Time Limit : 2000/1000ms (Java/Other) Memory Limit : 65536/32768K (Java/ ...
- HDU1142 A Walk Through the Forest(最短路+DAG)
A Walk Through the Forest Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/O ...
- A Walk Through the Forest
A Walk Through the Forest Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/O ...
- UVA - 10917 - Walk Through the Forest(最短路+记忆化搜索)
Problem UVA - 10917 - Walk Through the Forest Time Limit: 3000 mSec Problem Description Jimmy exp ...
随机推荐
- C#oracle备份和还原
最近公司的oracle备份工具不好使了,原来是公司的人用VB写的,由于我是主攻C#的,所以想着自己来写一个C#版本的oracle备份和还原工具. 一开始,我按照原来的设计思路来进行编写,想在pluss ...
- 绘制复杂的原理图元件和pcb封装库用于cadence(一)
绘制TI公司的TPS53319电源芯片封装 由于产品设计需要大电流电源供电,选用TI公司TPS53319电源芯片通过cadence软件进行电路设计,但是TI公司所提供的封装格式为CAD File(.b ...
- go查询mysql到list<map>
func selects() { db, err := sql.Open("mysql", "root:root@tcp(127.0.0.1:3306)/test?cha ...
- Java编程基础-运算符
Java中的运算符大致分为:算术运算符.赋值运算符.关系运算符.逻辑运算符和位运算符五类. (1).算术运算符:+ - * / % ++ -- (2).赋值运算符:= += -= * ...
- 16年毕业的前端er在杭州求职ing
来杭州也有一两个星期了,这个周末下雨,是在没地去,还是习惯性的打开电脑逛技术论坛,想想也是好久没有更新博文了... 背景 因为曾经看过一篇文章面试分享:一年经验初探阿里巴巴前端社招所以来杭州也是带有目 ...
- 涉及到弹出层的opacity样式问题
最近遇到一个弹出层在Chrome中重复的问题,观察发现是opacity引起的以下是代码及现象<!DOCTYPE html><html> <head> ...
- COGS 615. 韩国明星
[问题描述] 在LazyCat同学的影响下,Roby同学开始听韩国的音乐,并且越来越喜欢H.o.T,尤其喜欢安七炫和Tony,可是,爱学习爱思考的Roby同学想,如果以后喜欢的韩星越来越多怎么办呢?R ...
- (十二)mybatis之动态代理
mybatis之动态代理的应用 在前文(https://www.cnblogs.com/NYfor2018/p/9093472.html)我们知道了,Mybatis的使用需要用到Mapper映射文件, ...
- Linux系统里让vim支持markdown格式的语法高亮
Markdown是深受程序员喜爱的一个文件格式. 然而Linux里默认的vim设置,并不支持markdown格式的语法高亮显示. 下面就来介绍如何设置使得markdown格式的文件在vim里也能享有语 ...
- 使用python批量导入txt导入excel表格(公司电脑设备ip和人员统计)
#!/bin/env python # -*- encoding: utf- -*- import datetime import time import os import sys import x ...