高校计算机教育现状之学生

/* THE PROGRAM IS MADE BY PYY */
/*----------------------------------------------------------------------------//
Copyright (c) 2011 panyanyany All rights reserved.

URL   : http://acm.hdu.edu.cn/showproblem.php?pid=2112 Name  : 2112 HDU Today

Date  : Friday, January 13, 2012
Time Stage :

Result:
5250873	2012-01-13 10:05:57	Accepted	2112
2703MS	416K	1963 B
C++	pyy

5250866	2012-01-13 10:03:43	Wrong Answer	2112
2718MS	416K	1934 B
C++	pyy

Test Data :

Review :
这是个无向图，要判断有无重边。基本上属于模板题。
//----------------------------------------------------------------------------*/

#include <stdio.h>
#include <string.h>
#include <iostream>
#include <string>

using namespace std ;

#define INF		0x3f3f3f3f
#define MAXN	202

#define min(x, y)	((x) < (y) ? (x) : (y))

bool	used[MAXN] ;

int		n, iAreaCnt ;
int		map[MAXN][MAXN], dist[MAXN] ;

string	id[MAXN] ;

int getId (string str)
{
int i ;

for (i = 0 ; i < iAreaCnt ; ++i)
if (str == id[i])
return i ;

id[iAreaCnt] = str ;

return iAreaCnt++ ;
}

int dijkstra (const int start, const int end)
{
int i, j ;
int iMinPath, MinPath ;

memset (used, 0, sizeof (used)) ;
for (i = 0 ; i < iAreaCnt ; ++i)
{
dist[i] = map[start][i] ;
}

dist[start] = 0 ;

for (i = 0 ; i < iAreaCnt ; ++i)
{
iMinPath = 0 ;
MinPath = INF ;
for (j = 0 ; j < iAreaCnt ; ++j)
{
if (!used[j] && dist[j] < MinPath)
{
iMinPath = j ;
MinPath = dist[j] ;
}
}
used[iMinPath] = true ;
for (j = 0 ; j < iAreaCnt ; ++j)
if (!used[j] && dist[iMinPath] + map[iMinPath][j] < dist[j])
dist[j] = dist[iMinPath] + map[iMinPath][j] ;
}
if (dist[end] == INF)
return -1 ;
return dist[end] ;
}

int main (void)
{
int		i, j ;
int		start, end, x, y, c ;
string	a, b ;

while (scanf ("%d", &n), n != -1)
{
iAreaCnt = 0 ;

cin >> a >> b ;
start = getId (a) ;
end = getId (b) ;

memset (map, INF, sizeof (map)) ;

for (i = 0 ; i < n ; ++i)
{
cin >> a >> b >> c ;
x = getId (a) ;
y = getId (b) ;

map[x][y] = map[y][x] = min (map[x][y], c) ;
}

printf ("%d\n", dijkstra (start, end)) ;
}
return 0 ;
}