能过不代表程序没问题
> 这个题目我在ZOJ上通过，在这里提交就超时。
> 程序中没有多大的循环呀，真是bt。
> 还是看看程序吧！
> /* OnlinePID ZJU_1117 ( Entropy) */
> /* Huffman 算法 */
> #include <stdio.h>
> #include <string.h>
> #define INFINITY 99999999
> typedef struct{
>    int plink;
>    int weight;
> }Node;
> 
> Node node[60]; 
> int  cc; /* character count */
> int  orlen; /* ASCII bit len */ 
> 
> int input()
> {
>     char tmp[10000];  
>     int  i, j;
>     
>     scanf("%s", tmp);
>     if( strcmp(tmp, "END") == 0 ) return 0;
>     
>     for(i=0; i<=26; i++)
>     { node[i].weight = 0; node[i].plink = -1; }
>     
>     for(i=0; tmp[i]; i++)
>     {
>        if( tmp[i] != '_' ) j = tmp[i]-'A';
>        else                j = 26;
>        node[j].weight++;   node[j].plink = 0;
>     }
>     
>     for(orlen=cc=i=0; i<=26; i++) 
>       if( node[i].weight != 0 )
>       { orlen += node[i].weight * 8; cc++; }
>     return 1;
> }
> int huffman()
> {
>     int i, j, rets, t;
>     int w1, w2, x1, x2;
>     
>     for(i=1; i<=cc-1; i++)
>     {
>        /* select two small weight */
>        w1 = w2 = INFINITY; x2 = x1 = 0;
>        for(j=0; j<=26+i-1; j++)
>         if(node[j].plink == 0)
>         {
>            if(node[j].weight < w1 )
>            {  w2 = w1; x2 = x1;  w1 = node[j].weight; x1 = j; }
>            else if(node[j].weight < w2)
>            {  w2 = node[j].weight; x2 = j; }
>         }
>         
>        /* Add a new node, which weight is w1+w2 */
>        /* and set node x1, x2 's parent to new node */
>        node[26+i].weight = w1 + w2; 
>        node[26+i].plink = 0;      
>        node[x1].plink = node[x2].plink = 26+i;
>     }
>     /* Calc every character node 's depth in huffman tree */
>     /* and return sum of them */
>     for(rets=i=0; i<=26; i++)
>     {
>        j = i; t = 0;
>        while(node[j].plink != 0)
>        {  t++; j=node[j].plink; }
～～～～～～～～～～这里的j没判是不是不等于-1
改为while(j!=-1&&node[j].....
>        rets += node[i].weight * t;
>     }
>     return rets;
> }
>     
> int main()
> {
>     int oplen;
>     while( input() )
>     {
>        if(cc==1) oplen = orlen/8;
>        else oplen = huffman();
>        printf("%d %d %.1lf\n", orlen, oplen, (double)orlen/oplen);
>     }
>     return 0;
> }
>      

• 这个re很奇怪，vc也不能调试，debug模式就不报错，害的我看了好久才看出来 (73) hawk 2004-07-18 18:51:02
  • 一般都不报错的.它只是一个指针指向前面的一个数据而已.还是让别人来找莫名其妙的错误更容易.有时真希有个人来给我的RE程序找一下. (0) shushu 2006-03-18 12:29:16