Description

There are n cities numbered from 1 to n in Berland. Some of them are connected by two-way roads. Each road has its own length — an integer number from 1 to 1000. It is known that from each city it is possible to get to any other city by existing roads. Also for each pair of cities it is known the shortest distance between them. Berland Government plans to build k new roads. For each of the planned road it is known its length, and what cities it will connect. To control the correctness of the construction of new roads, after the opening of another road Berland government wants to check the sum of the shortest distances between all pairs of cities. Help them — for a given matrix of shortest distances on the old roads and plans of all new roads, find out how the sum of the shortest distances between all pairs of cities changes after construction of each road.

Input

The first line contains integer n (2 ≤ n ≤ 300) — amount of cities in Berland. Then there follow n lines with n integer numbers each — the matrix of shortest distances. j-th integer in the i-th row — di, j, the shortest distance between cities i and j. It is guaranteed that di, i = 0, di, j = dj, i, and a given matrix is a matrix of shortest distances for some set of two-way roads with integer lengths from 1 to 1000, such that from each city it is possible to get to any other city using these roads.

Next line contains integer k (1 ≤ k ≤ 300) — amount of planned roads. Following k lines contain the description of the planned roads. Each road is described by three space-separated integers aibici (1 ≤ ai, bi ≤ n, ai ≠ bi, 1 ≤ ci ≤ 1000) — ai and bi — pair of cities, which the road connects, ci — the length of the road. It can be several roads between a pair of cities, but no road connects the city with itself.

Output

Output k space-separated integers qi (1 ≤ i ≤ k). qi should be equal to the sum of shortest distances between all pairs of cities after the construction of roads with indexes from 1 to i. Roads are numbered from 1 in the input order. Each pair of cities should be taken into account in the sum exactly once, i. e. we count unordered pairs.

Sample Input

Input
2
0 5
5 0
1
1 2 3
Output
3 
Input
3
0 4 5
4 0 9
5 9 0
2
2 3 8
1 2 1
Output
17 12 

题目的大概意思是有n个城市,现给出这n个城市之间没两个城市的距离,改变一些城市的距离,问最后所有这些路径长度最小之和。
#include <iostream>
#include <algorithm>
using namespace std; int main()
{
long long n,m,a[310][310],sum,t1,t2,s;
while (cin>>n)
{
sum=0;
for (int i=1;i<=n;i++)
for (int j=1;j<=n;j++)
{
cin>>a[i][j];
sum+=a[i][j];
}
sum/=2; //没条路算了两次,多以要除以2。
cin>>m;
for (int p=1;p<=m;p++)
{
cin>>t1>>t2>>s;
if (a[t1][t2]<s)
{
cout <<sum<<endl;
continue;
}
for (int i=1;i<=n;i++) //检查一下改变一条路之后对其它路有没有影响
for (int j=1;j<=n;j++)
{
long long temp=a[i][t1]+s+a[t2][j];
if (temp<a[i][j]) //如果改变t1到t2的距离,看看i到t1再到t2再到i的距离是否比i直接到j的距离短,是的话则改变i到j的距离,同时改变j到i的距离。
{
sum=sum-(a[i][j]-temp);
a[i][j]=temp;
a[j][i]=temp;
}
}
cout <<sum<<endl;
}
}
return 0;
}

  

Roads in Berland(图论)的更多相关文章

  1. Codeforces Beta Round #25 (Div. 2 Only) C. Roads in Berland

    C. Roads in Berland time limit per test 2 seconds memory limit per test 256 megabytes input standard ...

  2. Day4 - M - Roads in Berland CodeForces - 25C

    There are n cities numbered from 1 to n in Berland. Some of them are connected by two-way roads. Eac ...

  3. 【Codeforces 25C】Roads in Berland

    [链接] 我是链接,点我呀:) [题意] 题意 [题解] 用floyd思想. 求出来这条新加的边影响到的点对即可. 然后尝试更新点对之间的最短路就好. 更新之后把差值从答案里面减掉. [代码] #in ...

  4. C. Roads in Berland

    题目链接: http://codeforces.com/problemset/problem/25/C 题意: 给一个最初的所有点与点之间的最短距离的矩阵.然后向图里加边,原有的边不变,问加边后的各个 ...

  5. 【CodeForces 567E】President and Roads(最短路)

    Description Berland has n cities, the capital is located in city s, and the historic home town of th ...

  6. CF 191C Fools and Roads lca 或者 树链剖分

    They say that Berland has exactly two problems, fools and roads. Besides, Berland has n cities, popu ...

  7. Codeforces Round #Pi (Div. 2) E. President and Roads tarjan+最短路

    E. President and RoadsTime Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/567 ...

  8. codeforces 228E The Road to Berland is Paved With Good Intentions(2-SAT)

    Berland has n cities, some of them are connected by bidirectional roads. For each road we know wheth ...

  9. codeforces 659E E. New Reform(图论)

    题目链接: E. New Reform time limit per test 1 second memory limit per test 256 megabytes input standard ...

随机推荐

  1. 在Wince模拟器接入网络的方法

    我第一次使用wince调用WCF服务的时候总是报错,找了半原因发现程序部署在模拟器中,而模拟器没有连接到网络,所以无法连接到WCF服务器. 以下是wince接入网络的方法:        1.点击模拟 ...

  2. css 完美替换图片

    1.css替换简单图标的展示方法 ;display:inline-block;position:absolute;left:11px;top:10px;border-right:6px solid t ...

  3. 小SQL大作用

    从DBA那问来的,备份现有数据库表: create table B select * from A ; 删除,重建数据库主键 alter table book_order drop primary k ...

  4. commons.fileupload简单应用

    导入包: commons-fileupload-1.3.1.jar commons-io-2.4.jar commons-fileupload依赖于commons-io,commons-io-2.4必 ...

  5. 错误:指定的任务可执行文件位置 D:\Android\platform-tools\aapt.exe 无效

    android-apt-compiler: Cannot run program "D:\android-sdk\platform-tools\aapt 装上IntelliJ IDEA /下 ...

  6. Network Attack

    Network Attack Nicola regularly inspects the local networks for security issues. He uses a smart and ...

  7. 【转】ubuntu下解压缩zip,tar,tar.gz和tar.bz2文件

    原文网址:http://blog.sina.com.cn/s/blog_5da93c8f0101h1uj.html 在Linux下面如何去压缩文件或者目录呢? 在这里我们将学习zip, tar, ta ...

  8. 最短路径问题:dijkstar

    算法描述: 输入图G,源点v0,输出源点到各点的最短距离D 中间变量v0保存当前已经处理到的顶点集合,v1保存剩余的集合 1.初始化v1,D 2.计算v0到v1各点的最短距离,保存到D for eac ...

  9. poj1363

    堆栈的模拟,给定序列,1,2,3,4,...判断堆栈出栈顺序是否合法 5 //5个数入栈1 2 3 4 5 //出栈顺序5 4 1 2 3 //出栈顺序0 //5个数的结束6 //6个数的入栈6 5 ...

  10. thinkjs初试

    背景          什么是thinkjs?thinkjs是奇舞团开源的一款NodejsMVC框架,该框架底层基于Promise来实现,很好的解决了Nodejs里异步回调的问题.我为什么会使用thi ...