【UOJ 216】最小花费最短路
【题目描述】:
给你n个点,m条无向边,每条边都有长度d和花费p,给你起点s终点t,要求输出起点到终点的最短距离及其花费,如果最短距离有多条路线,则输出花费最少的。
【输入描述】:
多组数据:每组数据描述如下:
输入n,m,点的编号是1~n,然后是m行,每行4个数 a,b,d,p,表示a和b之间有一条边,且其长度为d,花费为p。最后一行是两个数 s,t;起点s,终点t。
n和m为0时输入结束。
【输出描述】:
输出一行有两个数, 最短距离及其花费。
【样例输入】:
3 2
1 2 5 6
2 3 4 5
1 3
0 0
【样例输出】:
9 11
【时间限制、数据范围及描述】:
时间:1s 空间:128M
对于 30%的数据:1<n<=100
对于100%的数据:1<n<=1000; 0<m<100000; s != t; 1<=d,p<=1000
数据组数<=5,注意卡常;
题解:spfa,哇为什么就是过不了样例呢,找不出错误,难受.jpg
错解:
#include<cstdio> #include<iostream> #include<cmath> #include<cstdlib> #include<cstring> #include<algorithm> #include<queue> typedef long long ll; using namespace std; const int oo=21474836; int n,m,k,cnt,x,y,z,dis[100005],vis[100005]; struct node{ int to; int val; int next; int cos; }e[100005]; int head[100004]; int coo[100004],hh; void add(int a,int b,int c,int d){ cnt++; e[cnt].to=b; e[cnt].val=c; e[cnt].cos=d; e[cnt].next=head[a]; head[a]=cnt; } int main(){ freopen("216.in","r",stdin); freopen("216.out","w",stdout); while(1){ scanf("%d %d",&n,&m); queue<int>q; cnt=0; if(n==0 && m==0) break; for(int i=1;i<=m;i++){ scanf("%d %d %d %d",&hh,&x,&y,&z); add(hh,x,y,z); add(x,hh,y,z); } memset(head,0,sizeof(head)); memset(e,0,sizeof(e)); memset(dis,0x3f,sizeof(dis)); memset(coo,0x3f,sizeof(coo)); memset(vis,0,sizeof(vis)); int s,t; scanf("%d %d",&s,&t); q.push(s); dis[s]=0; coo[s]=0; vis[s]=1; while(!q.empty()){ x=q.front(); q.pop(); vis[x]=0; for(int i=head[x];i!=0;i=e[i].next){ int too=e[i].to; if(dis[too]>dis[x]+e[i].val){ dis[too]=dis[x]+e[i].val; coo[too]=coo[x]+e[i].cos; if(vis[too]==0) { vis[too]=1; q.push(too); } } if(dis[too]==dis[x]+e[i].val && coo[x]+e[i].cos<coo[too]){ dis[too]=dis[x]+e[i].val; coo[too]=coo[x]+e[i].cos; if(vis[too]==0) { vis[too]=1; q.push(too); } } } } printf("%d %d\n",dis[t],coo[t]); } return 0; }
感谢srj大佬给予修改找bug!!!orzTQL
#include<iostream> #include<cmath> #include<cstdlib> #include<cstring> #include<algorithm> #include<queue> typedef long long ll; using namespace std; const int oo=21474836; int n,m,k,cnt,x,y,z,dis[1000005];//,vis[100005]; struct node{ int to; int val; int next; int cos; }e[1000005]; int head[1000005]; int coo[1000005],hh; struct Node{ int pos,dis,cos; bool operator < ( const Node &a )const{ return a.dis==dis?a.cos<cos:a.dis<dis; } }; priority_queue<Node>q; void add(int a,int b,int c,int d){ cnt++; e[cnt].to=b; e[cnt].val=c; e[cnt].cos=d; e[cnt].next=head[a]; head[a]=cnt; } int main(){ freopen("216.in","r",stdin); freopen("216.out","w",stdout); while(1){ scanf("%d%d",&n,&m); cnt=0; if(n==0 && m==0) break; memset(head,0,sizeof(head)); memset(e,0,sizeof(e)); memset(dis,0x3f,sizeof(dis)); memset(coo,0x3f,sizeof(coo)); for(int i=1;i<=m;i++){ scanf("%d%d%d%d",&x,&hh,&y,&z); add(hh,x,y,z); add(x,hh,y,z); } int s,t; scanf("%d%d",&s,&t); q.push((Node){s,0,0}); dis[s]=0; coo[s]=0; while(!q.empty()){ Node tmp=q.top(); q.pop(); int x=tmp.pos; for(int i=head[x];i!=0;i=e[i].next){ int too=e[i].to; if(dis[too]>dis[x]+e[i].val){ dis[too]=dis[x]+e[i].val; coo[too]=coo[x]+e[i].cos; q.push((Node){too,dis[too],coo[too]}); } else if(dis[too]==dis[x]+e[i].val && coo[x]+e[i].cos<coo[too]){ dis[too]=dis[x]+e[i].val; coo[too]=coo[x]+e[i].cos; q.push((Node){too,dis[too],coo[too]}); } } } printf("%d %d\n",dis[t],coo[t]); } return 0; }