PAT A1111 Online Map（30 分）----最短路徑麻煩題
總結：最後一個測試點超時。。
1.這道題因為兩個要求，同時求的話要互不影響才行，就像求最短路徑的時候不能更新時間（重新設定個變數更新）
2.以求最快路徑為例，當totalen<minlen一定要更新totalsize,否則結果可能出錯
3.這種題優先採用dijstra方法
程式碼：
#include<iostream>
#include<vector>
#include<map>
using namespace std;
int n, m;
int G[600][600]; //長度
int ti[600][600];
int vi[600];
int st, end1;
int minlen=999999, totalen=0;
int mintime = 999999, totaltime = 0;
int mintime1 = 999999, totaltime1 = 0;
int totalsize = 0, minsize = 999999;
map<int, vector<vector<int>>> zuiduan;
map<int, vector<vector<int>>> zuikuai;
void dfs(int index,vector<int>duan,vector<int>kuai)
{
if (vi[index] == 1)return;
if (index == end1)
{
if (totalen < minlen){ minlen = totalen; mintime1 = totaltime1; zuiduan[minlen].push_back(duan); }
else if (totalen == minlen&&totaltime1 < mintime1){ mintime1 = totaltime1; minlen = totalen; zuiduan[minlen].push_back(duan); }
if (totaltime < mintime){ mintime = totaltime; minsize = totalsize; zuikuai[mintime].push_back(kuai); }
else if (totalsize<minsize&&totaltime == mintime){ minsize = totalsize; mintime = totaltime; zuikuai[mintime].push_back(kuai); }
}
vi[index] = 1;
for (int i = 0; i < n; i++)
{
if (vi[i] == 0 && G[index][i] != 0&&ti[index][i]!=0)
{
if(totalen>minlen&&totaltime>mintime)continue;
totalsize++;
totaltime += ti[index][i];
totalen += G[index][i];
totaltime1 += ti[index][i];
kuai.push_back(i);
duan.push_back(i);
dfs(i,duan,kuai);
totalsize--;
totalen -= G[index][i];
totaltime -= ti[index][i];
totaltime1 -= ti[index][i];
kuai.pop_back(); duan.pop_back();
vi[i] = 0;
}
}
}
int main()
{
cin >> n >> m;
for (int i = 0; i < m; i++)
{
int v1, v2, one, len, time;
scanf("%d%d%d%d%d",&v1,&v2,&one,&len,&time);
if (one == 1){ G[v1][v2] = len; ti[v1][v2] = time; }
else { G[v1][v2] = len; ti[v1][v2] = time; G[v2][v1] = len; ti[v2][v1] = time; }
}
cin >> st >> end1;
vector<int> duan;
vector<int> kuai;
duan.push_back(st);
kuai.push_back(st);
dfs(st,duan,kuai);
bool same = true;
int k1 = zuiduan[minlen].size(); int k2 = zuikuai[mintime].size();
if (zuiduan[minlen][zuiduan[minlen].size() - 1].size() == zuikuai[mintime][zuikuai[mintime].size() - 1].size())
{
for (int i = 0; i < zuiduan[minlen][zuiduan[minlen].size() - 1].size(); i++)
{
if (zuiduan[minlen][zuiduan[minlen].size() - 1][i] != zuikuai[mintime][zuikuai[mintime].size() - 1][i]){ same = false; break; }
}
}
else same = false;
if (same == true){
cout << "Distance = " << minlen << "; Time = " << mintime << ": ";
for (int i = 0; i < zuiduan[minlen][zuiduan[minlen].size() - 1].size(); i++)
{
printf("%d",zuiduan[minlen][zuiduan[minlen].size() - 1][i]);
if (i != zuiduan[minlen][zuiduan[minlen].size() - 1].size() - 1)printf(" -> ");
}
}
else{
cout << "Distance = "<<minlen<<": ";
for (int i = 0; i < zuiduan[minlen][zuiduan[minlen].size() - 1].size(); i++)
{
printf("%d", zuiduan[minlen][zuiduan[minlen].size() - 1][i]);
if (i != zuiduan[minlen][zuiduan[minlen].size() - 1].size() - 1)printf(" -> ");
}
cout << endl;
cout << "Time = "<<mintime<<": ";
for (int i = 0; i < zuikuai[mintime][zuikuai[mintime].size() - 1].size(); i++)
{
printf("%d", zuikuai[mintime][zuikuai[mintime].size() - 1][i]);
if (i != zuikuai[mintime][zuikuai[mintime].size() - 1].size() - 1)printf(" -> ");
}
}
return 0;
}
參考程式碼：
#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;
}