HDU-2544-最短路-模板

来源：互联网发布：js设置input的value 编辑：程序博客网时间：2024/06/07 18:04

//Dijkstra-感觉和prim很像，就是很像#include<stdio.h>#include<string.h>#include<stdlib.h>#define MAX 0x3f3f3fint map[150][150];int dis[150];int n;int bj[150];void dijkstra(){    memset(bj,0,sizeof(bj));    memset(dis,0,sizeof(dis));    int pos = 1,i,j;    for(i = 1; i <= n; i++)        dis[i] = map[pos][i];        bj[1] = 1;    for(i = 1; i < n; i++)    {        int min = MAX;        for(j = 1; j <= n; j++)        {            if(min > dis[j] && !bj[j])                min = dis[pos = j];        }        bj[pos] = 1;        for(j = 1; j <= n; j++)        {            if(dis[j] > map[pos][j]+dis[pos]&& !bj[j])                dis[j] = map[pos][j]+dis[pos];        }    }    printf("%d\n",dis[n]);}int main(){    int m;    while(~scanf("%d%d",&n,&m))    {        int i, j;        for(i = 1; i <= n; i++)            for(j = 1; j <= n; j++)                if(i!=j)                   map[i][j] = MAX;          int u, v, w;          for(i = 0;i < m; i++)          {              scanf("%d%d%d",&u,&v,&w);              if(map[u][v]>w)              {               map[u][v] = w;               map[v][u] = w;               }          }         dijkstra();    }    return 0;}

Bellman-ford，和krusal感觉很像，也可能是错觉

#include<stdio.h>#include<string.h>#include<stdlib.h>#define MAX 0x3f3f3fint n,m, cont;struct node{    int u,v,w;}ls[15000];void BF(){    int dis[200];    for(int i = 0; i <= n; i++)        dis[i] = MAX;        dis[1] = 0;    for(int i = 1; i < n; i++)        for(int j = 0; j < cont; j++)       {           int a = ls[j].u, b = ls[j].v;          if(dis[b] > dis[a] + ls[j].w)            dis[b] = dis[a] + ls[j].w;       }       printf("%d\n",dis[n]);}int main(){    while(~scanf("%d%d",&n,&m)&&(n+m))    {        int i;        cont = 0;        for(i = 0; i < m; i++)        {            int u, v, w;            scanf("%d%d%d",&u,&v,&w);            int flag = 0;            for(int j = 0; j < cont; j++)            {                if((ls[j].u == u && ls[j].v == v)||(ls[j].u == v && ls[j].v == u))                    if(ls[j].w > w)                    {                     ls[j].w = w;                     flag = 1;                    }            }            if(!flag)            {                ls[cont].u = u;                ls[cont].v = v;                ls[cont++].w = w;                ls[cont].u = v;                ls[cont].v = u;                ls[cont++].w = w;            }        }       BF();    }    return 0;}

Floyd,感觉像暴力

#include<stdio.h>#include<string.h>#include<stdlib.h>#define MAX 0x3f3f3fint n,m;int map[200][200];void Floyd(){    int i, j, k;    for(i = 0;i <= n; i++)        for(j = 0; j <= n; j++)           for(k = 0; k <= n; k++)             if(map[k][i] + map[i][j] < map[k][j])                  map[k][j] = map[k][i]+map[i][j];    printf("%d\n",map[1][n]);}int main(){    while(~scanf("%d%d",&n,&m)&&(n+m))    {        int i,j;        for(i = 0; i <= n; i++)            for(j = 0; j <= n; j++)              if(i != j)              map[i][j] = MAX;        for(i = 0; i < m; i++)        {            int u, v, w;            scanf("%d%d%d",&u,&v,&w);            if(map[u][v] > w)            {                map[u][v] = w;                map[v][u] = w;            }        }        Floyd();    }    return 0;}

SPFA 是在BF上优化的，加了队列，

#include<stdio.h>#include<string.h>#include<stdlib.h>#include<algorithm>#include<iostream>#include<queue>#define Maxn 150#define Maxm 10000#define Max 10000using namespace std;int head[Maxm],bj[Maxn],dis[Maxn];int pos[Maxn];int n,m;struct node{    int v, w, next;}ls[20000];bool SPFA(int start){    queue<int>a;    for(int i = 0; i <= n; i++)        dis[i] = 9999999;    bj[start] = 1;    dis[start] = 0;    a.push(start);    while(!a.empty())    {        int top = a.front();        a.pop();        pos[top]++;        bj[top] = 0;        if(pos[top] > n) return false;        for(int i = head[top]; i!=-1;i = ls[i].next)        {            if(dis[ls[i].v] > dis[top] + ls[i].w)            {                dis[ls[i].v] = dis[top] + ls[i].w;               if(!bj[ls[i].v])               {                bj[ls[i].v] = 1;                a.push(ls[i].v);               }            }        }    }    return true;}int main(){  while(~scanf("%d%d",&n,&m)&&(n+m))  {      memset(head,-1,sizeof(head));      memset(pos,0,sizeof(pos));      int k = 0;      while(m--)      {          int u, v, w;          scanf("%d%d%d",&u,&v,&w);          ls[k].v = v;          ls[k].w = w;          ls[k].next = head[u];          head[u] = k++;          ls[k].v = u;          ls[k].w = w;          ls[k].next = head[v];          head[v] = k++;      }      if(SPFA(1))        printf("%d\n",dis[n]);  }  return 0;}

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