题意:给一张地图,两个结点中既有距离也有时间,有的单行有的双向,要求根据地图推荐两条路线:一条是最快到达路线,一条是最短距离的路线。
第一行给出两个整数N和M,表示地图中地点的个数和路径的条数。接下来的M行每一行给出:道路结点编号V1 道路结点编号V2 是否单行线 道路长度 所需时间
要求第一行输出最快到达时间Time和路径,第二行输出最短距离Distance和路径
tip:DFS + Dijkstra
DFS版
#include<iostream>
#include<vector>
#include<cstring>
#include<algorithm>
using namespace std;
int mapd[503][503];
int mapt[503][503];
vector<int>map[503];
vector<int>dist,tim,temp;
int n,m,s,e,mincost=1e7;
int mincount=1e7,minlen=1e7,minspend=1e7,checked[503]= {0};
void dfsdistance(int t,int len,int spend) {
checked[t]=1;
temp.push_back(t);
if(len>minlen)
return ;
if(t==e) {
mincost=min(mincost,spend);
if(minlen==len) {
if(minspend>spend) {
minspend=spend;
dist=temp;
}
} else if(minlen>len) {
minlen=len;
minspend=spend;
dist=temp;
}
return ;
}
for(int i=0; i<map[t].size(); ++i)
if(!checked[map[t][i]]) {
dfsdistance(map[t][i],len+mapd[t][map[t][i]],mapt[t][map[t][i]]+spend);
checked[map[t][i]]=0;
temp.pop_back();
}
}
void dfstime(int t,int spend,int count) {
checked[t]=1;
temp.push_back(t);
if(spend>mincost)
return ;
if(t==e) {
if(mincost==spend) {
if(mincount>count) {
mincount=count;
tim=temp;
}
} else if(mincost>spend) {
mincount=count;
mincost=spend;
tim=temp;
}
return ;
}
for(int i=0; i<map[t].size(); ++i)
if(!checked[map[t][i]]) {
dfstime(map[t][i],spend+mapt[t][map[t][i]],count+1);
checked[map[t][i]]=0;
temp.pop_back();
}
}
int main() {
scanf("%d %d",&n,&m);
memset(mapd,0,sizeof(mapd));
memset(mapt,0,sizeof(mapt));
for(int i=0; i<m; ++i) {
int a,b,way,len,time;
scanf("%d %d %d %d %d",&a,&b,&way,&len,&time);
mapd[a][b]=len;
mapt[a][b]=time;
map[a].push_back(b);
if(!way) {
mapd[b][a]=len;
mapt[b][a]=time;
map[b].push_back(a);
}
}
scanf("%d %d",&s,&e);
dfsdistance(s,0,0);
temp.clear();
memset(checked,0,sizeof(checked));
dfstime(s,0,1);
if(dist==tim) {
printf("Distance = %d; Time = %d: %d",minlen,mincost,tim[0]);
for(int i=1; i<tim.size(); ++i)
printf(" -> %d",tim[i]);
} else {
printf("Distance = %d: %d",minlen,dist[0]);
for(int i=1; i<dist.size(); ++i)
printf(" -> %d",dist[i]);
printf("\nTime = %d: %d",mincost,tim[0]);
for(int i=1; i<tim.size(); ++i)
printf(" -> %d",tim[i]);
}
return 0;
}
Dijkstra版
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
const int inf = 999999999;
int dis[510], Time[510], e[510][510], w[510][510], dispre[510],Timepre[510], weight[510],NodeNum[510];
bool visit[510];
vector<int> dispath, Timepath, temppath;
int st, fin, minnode = inf;
void dfsdispath(int v) {
dispath.push_back(v);
if(v == st) return ;
dfsdispath(dispre[v]);
}
void dfsTimepath(int v) {
Timepath.push_back(v);
if(v == st) return ;
dfsTimepath(Timepre[v]);
}
int main() {
fill(dis, dis + 510, inf);
fill(Time, Time + 510, inf);
fill(weight, weight + 510, inf);
fill(e[0], e[0] + 510 * 510, inf);
fill(w[0], w[0] + 510 * 510, inf);
int n, m;
scanf("%d %d", &n, &m);
int a, b, flag, len, t;
for(int i = 0; i < m; i++) {
scanf("%d %d %d %d %d", &a, &b, &flag, &len, &t);
e[a][b] = len;
w[a][b] = t;
if(flag != 1) {
e[b][a] = len;
w[b][a] = t;
}
}
scanf("%d %d", &st, &fin);
dis[st] = 0;
for(int i = 0; i < n; i++)
dispre[i] = i;
for(int i = 0; i < n; i++) {
int u = -1, minn = inf;
for(int j = 0; j < n; j++) {
if(visit[j] == false && dis[j] < minn) {
u = j;
minn = dis[j];
}
}
if(u == -1) break;
visit[u] = true;
for(int v = 0; v < n; v++) {
if(visit[v] == false && e[u][v] != inf) {
if(e[u][v] + dis[u] < dis[v]) {
dis[v] = e[u][v] + dis[u];
dispre[v] = u;
weight[v] = weight[u] + w[u][v];
} else if(e[u][v] + dis[u] == dis[v] && weight[v] > weight[u] + w[u][v]) {
weight[v] = weight[u] + w[u][v];
dispre[v] = u;
}
}
}
}
dfsdispath(fin);
Time[st] = 0;
fill(visit, visit + 510, false);
for(int i = 0; i < n; i++) {
int u = -1, minn = inf;
for(int j = 0; j < n; j++) {
if(visit[j] == false && minn > Time[j]) {
u = j;
minn = Time[j];
}
}
if(u == -1) break;
visit[u] = true;
for(int v = 0; v < n; v++) {
if(visit[v] == false && w[u][v] != inf) {
if(w[u][v] + Time[u] < Time[v]) {
Time[v] = w[u][v] + Time[u];
Timepre[v]= u;
NodeNum[v]=NodeNum[u]+1;
} else if(w[u][v] + Time[u] == Time[v]&&NodeNum[u]+1<NodeNum[v]) {
Timepre[v]= u;
NodeNum[v]=NodeNum[u]+1;
}
}
}
}
dfsTimepath(fin);
printf("Distance = %d", dis[fin]);
if(dispath == Timepath) {
printf("; Time = %d: ", Time[fin]);
} else {
printf(": ");
for(int i = dispath.size() - 1; i >= 0; i--) {
printf("%d", dispath[i]);
if(i != 0) printf(" -> ");
}
printf("\nTime = %d: ", Time[fin]);
}
for(int i = Timepath.size() - 1; i >= 0; i--) {
printf("%d", Timepath[i]);
if(i != 0) printf(" -> ");
}
return 0;
}
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