hdu 1874 最短路练习

//SPFA
#include<bits/stdc++.h>
using namespace std;
const int maxn=205;

struct node
{
int point,edge;
};
vector<node>e[maxn];

int n,m;

int dis[maxn],inq[maxn];

queue<int>q;

void init()
{
int i;
for(i=0;i<maxn;++i)  e[i].clear();
for(i=0;i<maxn;++i)  dis[i]=1e9;
for(i=0;i<maxn;++i)  inq[i]=0;
}
int main()
{
int i,j,k;
while(scanf("%d%d",&n,&m)!=EOF)
{

init();
for(i=0;i<m;++i)
{
int x,y,z;
node a1,a2;
scanf("%d%d%d",&x,&y,&z);
a1.point=y;a2.edge=a1.edge=z;
a2.point=x;
e[x].push_back(a1);
e[y].push_back(a2);
}

int s,t;
scanf("%d%d",&s,&t);
q.push(s);inq[s]=1;dis[s]=0;

while(!q.empty())
{
int now;
now=q.front();
q.pop();inq[now]=0;

int len;
len=e[now].size();
for(i=0;i<len;++i)
{
int v=e[now][i].point;
int value=e[now][i].edge;
if(dis[v]>dis[now]+value)
{
dis[v]=dis[now]+value;
if(!inq[v])
q.push(v);
inq[v]=1;
}
}
}
if(dis[t]==1e9)
printf("-1\n");
else
printf("%d\n",dis[t]);
}
return 0;
}

//dijkstra
#include<bits/stdc++.h>
using namespace std;

const int maxn=205,maxm=1e5+7;

int n,m;

int sz;
int fir[maxn],nxt[maxm],to[maxm],val[maxm];

void add(int x,int y,int z)
{
nxt[++sz]=fir[x];
fir[x]=sz;
to[sz]=y;
val[sz]=z;
}

//vector<pair<int,int> >e[maxn];
int dis[maxn];
priority_queue<pair<int,int> >q;

void init()
{
sz=0;
for(int i=0;i<maxn;++i)
{
dis[i]=1e9;
fir[i]=0;
}
}
int main()
{
int i ,j,k;
while(cin>>n>>m)
{
init();
for(i=0;i<m;++i)
{
int x,y,z;
scanf("%d%d%d",&x,&y,&z);
add(x,y,z);
add(y,x,z);
//e[x].push_back(make_pair(y,z));
//e[y].push_back(make_pair(x,z));
}

int s,t;
scanf("%d%d",&s,&t);
dis[s]=0;q.push(make_pair(-dis[s],s));
while(!q.empty())
{
int now=q.top().second;
q.pop();

for(int u=fir[now];u;u=nxt[u])
{
int v=to[u];
int value=val[u];
if(dis[v]>dis[now]+value)
{
dis[v]=dis[now]+value;
q.push(make_pair(-dis[v],v));
}
}
}
if(dis[t]==1e9) printf("-1\n");
else  printf("%d\n",dis[t]);
}
return 0;
}

// dijkstra
// hdu 1878
#include<bits/stdc++.h>
using namespace std;

const int maxn=206;

struct edge{
int v,va;
};
vector<edge>e[maxn];

struct data{
int d,p;

friend bool operator<(data a,data b)
{
return a.d>b.d;
}
//  bool operator<(const data &a) const{
//      return a.d<d;
//  }
};
/*
bool operator < (const data &a,const data &b)
{
if(a.d>b.d)  return 1;
return 0;
}

bool operator < (const data a,const data b)
{
if(a.d>b.d)  return 1;
return 0;
}

bool operator < (data a,data b)
{
if(a.d>b.d)  return 1;
return 0;
}
*/
priority_queue<data>q;

int n,m;
int dis[maxn];

void prein()
{
for(int i=0;i<maxn;++i)
{
e[i].clear();
dis[i]=1e9;
}
}

int main()
{
int i,j,k;
while(scanf("%d%d",&n,&m)!=EOF)
{
prein();

for(i=0;i<m;++i)
{
int x,y,z;
scanf("%d%d%d",&x,&y,&z);
edge te;
te.v=y;te.va=z;e[x].push_back(te);
te.v=x;e[y].push_back(te);
}

int s,t;
scanf("%d%d",&s,&t);
dis[s]=0;
data temp;
temp.d=dis[s];temp.p=s;
q.push(temp);
while(!q.empty())
{
int now=q.top().p;
q.pop();
int len=e[now].size();
for(i=0;i<len;++i)
{
int v=e[now][i].v;
int va=e[now][i].va;
if(dis[v]>dis[now]+va)
{
dis[v]=dis[now]+va;
temp.d=dis[v];temp.p=v;
q.push(temp);
}
}
}
if(dis[t]==1e9)
dis[t]=-1;
printf("%d\n",dis[t]);
}
return 0;
}