记录编号 |
118318 |
评测结果 |
AAAAAAAAAA |
题目名称 |
[USACO Feb07] 奶牛聚会 |
最终得分 |
100 |
用户昵称 |
HouJikan |
是否通过 |
通过 |
代码语言 |
C++ |
运行时间 |
0.008 s |
提交时间 |
2014-09-06 10:40:26 |
内存使用 |
0.35 MiB |
显示代码纯文本
#include <iostream>
#include <cstring>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <list>
#include <vector>
#include <ctime>
#include <iterator>
#include <functional>
#define pritnf printf
#define scafn scanf
#define For(i,j,k) for(int i=(j);i<=(k);(i)++)
using namespace std;
typedef long long LL;
typedef unsigned int Uint;
const int INF=0x7ffffff;
//==============struct declaration==============
struct adj
{
int to,dist;
adj(int to=0,int dist=0):to(to),dist(dist){}
};
//==============var declaration=================
const int MAXN=1010;
int n,m,s;
int d1[MAXN],d2[MAXN];
bool inq[MAXN];
vector <adj> Edge1[MAXN],Edge2[MAXN];
//==============function declaration============
void spfa(vector <adj> *Edge,int *d);
//==============main code=======================
int main()
{
string FileName="sparty";//程序名
string FloderName="COGS";//文件夹名
freopen((FileName+".in").c_str(),"r",stdin);
freopen((FileName+".out").c_str(),"w",stdout);
#ifdef DEBUG
system(("cp C:\\Users\\Administrator\\Desktop\\"+FloderName+"\\standard.cpp C:\\Users\\Administrator\\Desktop\\"+FloderName+"\\submit.txt").c_str());
clock_t Start_Time=clock();
#endif
scanf("%d%d%d",&n,&m,&s);
int from,to,dist;
For(i,1,m)
{
scanf("%d%d%d",&from,&to,&dist);
Edge1[from].push_back(adj(to,dist));
Edge2[to].push_back(adj(from,dist));
}
spfa(Edge1,d1);
spfa(Edge2,d2);
int maxt=0;
For(i,1,n)
maxt=max(maxt,d1[i]+d2[i]);
cout<<maxt<<endl;
#ifdef DEBUG
clock_t End_Time=clock();
cout<<endl<<endl<<"Time Used: "<<End_Time-Start_Time<<endl;
#endif
return 0;
}
//================fuction code====================
void spfa(vector <adj> *Edge,int *d)
{
For(i,1,n)
d[i]=INF;
d[s]=0;
queue <int>Q;
Q.push(s);
memset(inq,false,sizeof(inq));
while (!Q.empty())
{
int now=Q.front();Q.pop();
inq[now]=false;
int siz=Edge[now].size()-1;
For(i,0,siz)
{
adj &e=Edge[now][i];
if (d[e.to]>d[now]+e.dist)
{
d[e.to]=d[now]+e.dist;
if (!inq[e.to])
Q.push(e.to);
inq[e.to]=true;
}
}
}
}