Shortest Path algorithm

Shortest Path algorithm 1--floyed and Dijkstra algorithm.

To find the shortest path of a point to another point in the graph, there is no doubt that the floyed algorithm is the simplest, and is a multi-source shortest path, but the time complexity is very high to reach O (n^3).

The principle is to constantly traverse all points on one side, and treat them as intermediate points, updating the entire graph every time.

Floyed Code:

1#include <cstdio>2#include <iostream>3 #defineN 42004 using namespacestd;5 intN,m,p,q,a,b,c,dis[n][n];6 intMain () {7scanf"%d%d%d%d",&n,&m,&p,&q);8      for(intI=1; i<=n;++i)9          for(intj=1; j<=n;++j)Tendis[i][j]=4200000; One      for(intI=1; i<=m;++i) { Ascanf"%d%d%d",&a,&b,&c); -dis[a][b]=C; -dis[b][a]=C; the     } -      for(intk=1; k<=n;++k) -          for(intI=1; i<=n;++i) -              for(intj=1; j<=n;++j) +Dis[i][j]=min (dis[i][j],dis[i][k]+dis[k][j]); -printf"%d", Dis[p][q]); +     return 0; A}

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Shortest Path algorithm