最短路模板[spfa][dijkstra+堆优化][floyd]

借bzoj1624练了一下模板（虽然正解只是floyd）

spfa:

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <iostream>
#include <vector>
#include <queue>
using namespace std;
const int INF=100001;
const int maxm=10001,maxn=101;

int n,m,x,y,w;
long long ans=0;
int a[maxm];
int dist[maxn];
bool vis[maxn];
struct edge{
	int to,w;
	edge(int _to,int _w){to=_to;w=_w;}
};
vector <edge> g[maxm];

void spfa(int x){
	queue<int> q;
	memset(dist,63,sizeof(dist));
	memset(vis,false,sizeof(vis));
	dist[x]=0;
	vis[x]=1;
	q.push(x);

	while(!q.empty()){
		int u=q.front();
		q.pop();
		vis[u]=0;
		int l=g[u].size();
		for(int i=0;i<l;i++){
			int v=g[u][i].to;
			if(dist[v]>dist[u]+g[u][i].w){
				dist[v]=dist[u]+g[u][i].w;
			    if(!vis[v]){
			    	vis[v]=1;q.push(v);
			    }
			}
		}
	}
}

int main(){
	freopen("data.in","r",stdin);
	freopen("text.out","w",stdout);
	//freopen("data.txt","r",stdin);
	scanf("%d%d",&n,&m);
	for(int i=1;i<=m;i++) scanf("%d",&a[i]);
	for(int i=1;i<=n;i++)
	    for(int j=1;j<=n;j++){
	    	scanf("%d",&w);
	    	if(i!=j) g[i].push_back(edge(j,w));
	    }
	for(int i=1;i<m;i++){
		spfa(a[i]);
		ans+=dist[a[i+1]];
	}
	cout<<ans;
	return 0;
}

　　

dijkstra+priority_queue:

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <iostream>
#include <vector>
#include <queue>
using namespace std;
const int INF=100001;
const int maxm=10001,maxn=101;

int n,m,x,y,w;
long long ans=0;
int a[maxm];
int dist[maxn];
struct edge{
	int to,w;
	edge(int _to,int _w){to=_to;w=_w;}
};
vector <edge> g[maxm];
typedef pair<int,int> P;

void dijkstra(int x){
	priority_queue< P , vector <P> , greater<P> > q;
	memset(dist,63,sizeof(dist));
	dist[x]=0;
	q.push(P(0,x));

	while(!q.empty()){
		P u=q.top();
		int x=u.second;
		q.pop();
		if(dist[x]<u.first) continue;
		int l=g[x].size();
		for(int i=0;i<l;i++){
			int v=g[x][i].to;
			if(dist[v]>dist[x]+g[x][i].w){
				dist[v]=dist[x]+g[x][i].w;
			    q.push(P(dist[v],v));
			}
		}
	}
}

int main(){
	freopen("danger.in","r",stdin);
	freopen("danger.out","w",stdout);
	//freopen("data.txt","r",stdin);
	scanf("%d%d",&n,&m);
	for(int i=1;i<=m;i++) scanf("%d",&a[i]);
	for(int i=1;i<=n;i++)
	    for(int j=1;j<=n;j++){
	    	scanf("%d",&w);
	    	if(i!=j) g[i].push_back(edge(j,w));
	    }
	for(int i=1;i<m;i++){
		dijkstra(a[i]);
		ans+=dist[a[i+1]];
	}
	cout<<ans;
	return 0;
}

　　
floyd:

#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cmath>
#include<cstring>
#include<string>
#include<queue>
#include<stack>
#include<vector>
using namespace std;
int n,m,i,j,k,ans,f[102][102],a[10002];
int main(){
  cin>>n>>m;
  for(i=1;i<=m;i++)scanf("%d",&a[i]);
  for(i=1;i<=n;i++)
  for(j=1;j<=n;j++)
    scanf("%d",&f[i][j]);
  for(k=1;k<=n;k++)
  for(i=1;i<=n;i++)
  for(j=1;j<=n;j++)
    f[i][j]=min(f[i][j],f[i][k]+f[k][j]);
  for(i=2;i<=m;i++)ans+=f[a[i-1]][a[i]];
  cout<<ans;
  return 0;
}