[kuangbin带你飞]专题四 最短路练习 G MPI Maelstrom

#include<iostream>
#include<cstring>
#include<algorithm>
#include<iomanip>
#include<cmath>
#include<cstdio>
#include<vector>
using namespace std;
#define MAXN 101
#define INF 0x3f3f3f3f
/*
8:19
8:35 题意理解太慢：在所有最短路路中间一条最长的
8:52 sscanf用法
8:57 忘记BEEN,g[i][j] = g[j][i]双向
*/
int n;
bool been[MAXN];
int g[MAXN][MAXN],lowcost[MAXN];
int Dijkstra()
{
memset(lowcost,INF,sizeof(lowcost));
memset(been,false,sizeof(been));
lowcost[1] = 0;
for(int j=0;j<n;j++)
{
int Min = INF,k = -1;
for(int i=1;i<=n;i++)
{
if(!been[i]&&lowcost[i]<Min)
{
Min = lowcost[i];
k = i;
}
}
if(k==-1) break;
been[k] = true;
for(int i=1;i<=n;i++)
{
if(!been[i]&&lowcost[i]>lowcost[k]+g[k][i])
{
lowcost[i] = lowcost[k]+g[k][i];
}
}
}
int Max = -1;
for(int i=1;i<=n;i++)
{
Max = max(Max,lowcost[i]);
}
return Max;
}
int main()
{
cin>>n;
char s[30];
memset(g,INF,sizeof(g));
for(int i=1;i<=n;i++)
{
for(int j=1;j<i;j++)
{
cin>>s;
if(s[0]=='x')
{
g[i][j] = g[j][i]= INF;
}
else
{
sscanf(s,"%d",&g[i][j]);
g[j][i] = g[i][j];
}
}
}
int ans =Dijkstra();
cout<<ans<<endl;
return 0;
}