Dijkstra 算法寻找最短路径 较简易

反正觉得比书上的代码简单多了

主要的一些核心代码还是参考上一篇博客的，觉得那篇的Dij写的不错，值得细细品味

注释的话看上篇博客，vim不知道怎么注释

#include<iostream>
using namespace std ;
const int maxint = 999 ;
const int maxnum = 100 ;
int dist[maxnum] ;
int pre[maxnum] ;
int c[maxnum][maxnum] ;

void Dij(int number , int sn ,int *dist ,int *pre , int c[maxnum][maxnum]){
		bool s[maxnum] ;
		for(int i = 1 ;i<= number ;i++) {
			dist[i] = c[sn][i]	;
			s[i] = 0 ;
			if(dist [i] == maxint ){
				pre[i] = 0 ;
			}
			else {
				pre[i] = sn ;
			}
		}
		dist [sn] = 0 ;
		s[sn] = 1 ;
		for(int i = 2 ;i<= number ;i++) {
			int pas = maxint ;
			int u = sn;
			for(int j = 1 ;j<= number ;j++ )
				if((!s[j]) && dist[j] <pas) {
					u = j ;
					pas = dist[j] ;
				}
			s[u] = 1 ;
			for(int j = 1;j<=number ;j++) {
				if((!s[j]) && c[u][j] <maxint ) {
					int newdist = dist[u] +c[u][j] ;
					if(newdist < dist[j]){
						dist[j] = newdist ;
						pre[j] = u ;
					}
				}
			}
		}
}
void SearchPath (int sour_num ,int want_num){
	cout << "the best way to want_num 's distance is  ";
	cout << dist[want_num] ;
}
int main () {
	cout << "input the number of Graph :" <<endl;
	int number ;
	cin >> number ;
	cout << "input the line-number of Graph " <<endl ;
	int line_n ;
	cin >> line_n ;
	int a , b ,len ;
	for(int i = 1 ;i <= number ;i++) {
		for( int j = 1 ;j <= number ; j++) {
			c[i][j] = maxint ;
		}
	}
	for(int i = 1 ; i <= line_n ;i++ ) {
		cin >> a >> b >> len ;
		if(len < c[a][b] ){
			c[a][b] = len ;
			c[b][a] = len ;
		}
	}
	for(int i = 1;i <= number ;i++) {
			dist[i] = maxint ;
	}
	for(int i = 1 ;i <= number ;i++) {
		for(int j = 1; j<= number; j++) {
			cout << c[i][j]<< " " ;
		}
		cout << endl ;
	}
	cout <<"use the Dij ..." <<endl ;
	Dij(number , 1 , dist , pre ,c) ;
	cout << "input  the want_num :" <<endl ;
	int want_num ;
	cin >> want_num ;
	SearchPath (1, want_num) ;
}