标签:blog io os for sp div on log bs
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;
}
最短路模板[spfa][dijkstra+堆优化][floyd]
标签:blog io os for sp div on log bs
原文地址:http://www.cnblogs.com/polebug/p/4072713.html