pat 甲级 1003

pat 甲级 1003
用了个笨方法,dfs所有路径,在比较.
#include<bits/stdc++.h>
using namespace std;
#define MAXN 500
struct EDGE
{
int from, to, value, next;
} edge[MAXN*MAXN];

int head[MAXN];
int number[MAXN];
int n,m,current,save;
bool visit[MAXN];
int shortest_path = 0x3f3f3f3f;
int cnt = 0;
int ways = 0;

void short_path(int v,int num, int d)
{
//cout<<"-------"<<v<<"------------"<<endl;
if(d > shortest_path)
return;
if(v == save)
{
d+=number[v];
if(d<shortest_path)
{
shortest_path = d;
ways = 1;
cnt = num;
//cout<<"-------success------------"<<endl;
}
else if(d == shortest_path)
{
cnt = cnt>num?cnt:num;
ways++;
//cout<<"-------success------------"<<endl;
}
return;
}
visit[v] = true;
for(int k = head[v];k!=-1;k = edge[k].next)
{
int temp = edge[k].to;
if(!visit[temp])
short_path(temp,num+number[temp],d+edge[k].value);
}
visit[v] = false;
}

int main()
{
int c1, c2, d;
cin>>n>>m>>current>>save;
for(int i = 0;i<n;i++)
cin>>number[i];
memset(head,-1,sizeof(head));
for(int i = 0;i<n*n;i++)
edge[i].next = -1;

for(int i = 0;i<m;i++)
{
cin>>c1>>c2>>d;
edge[i<<1].from = c1;
edge[i<<1].to = c2;
edge[i<<1].value = d;
edge[i<<1].next = head[c1];
head[c1] = i<<1;

edge[(i<<1)^1].from = c2;
edge[(i<<1)^1].to = c1;
edge[(i<<1)^1].value = d;
edge[(i<<1)^1].next = head[c2];
head[c2] = i<<1^1;
}
short_path(current,number[current],0);
cout<<ways<<' '<<cnt;
return 0;
}