POJ 1002

 qsort的运行，具体看MSDN

    一个是二位数组的qsort用法：

1int compare( const void *arg1, const void *arg2 ) 
2{ 
3   return strcmp((char*)arg1, (char*)arg2 ); 
4} 
5int arr[n][11]; 
6qsort(arr, n, sizeof(arr[0]), compare);
注意：width: Element size in bytes
               cmp函数：如果是升序，则e1 > e2应返回1，e1 = e2 应返回0， e1 < e2 应返回-1.降序则相反。
#include <stdio.h>#include <string.h>#include <stdlib.h>#define csMax 100000+1char nNumber[csMax][50];char nC_Number[csMax][20];//新学的字符按照字典序排序int cmp(const void *a, const void *b){return strcmp((char *)a, (char *)b);}int main(){int i, j, k;int nCase, len;int count, flag;char map[100];map['A']=map['B']=map['C']='2';map['D']=map['E']=map['F']='3';map['G']=map['H']=map['I']='4';map['J']=map['K']=map['L']='5';map['M']=map['N']=map['O']='6';map['P']=map['S']=map['R']='7';map['T']=map['U']=map['V']='8';map['W']=map['X']=map['Y']='9';while (1==scanf("%d", &nCase)){for(i=0; i<nCase; i++){scanf(" %s", nNumber[i]);len=strlen(nNumber[i]);k=0;for(j=0; j<len; j++){if(nNumber[i][j]>='0'&&nNumber[i][j]<='9')nC_Number[i][k++]=nNumber[i][j];else if(nNumber[i][j]>='A'&&nNumber[i][j]<='Z'&&map[nNumber[i][j]]>0)nC_Number[i][k++]=map[nNumber[i][j]];}//nC_Number[i][k]='/0';}qsort(nC_Number, nCase,sizeof(nC_Number[0]), cmp);//输出方法太不朴素了！flag=0;for(i=0; i<nCase-1; i++){count=1;for(j=i+1; j<nCase; j++){if(!strcmp(nC_Number[i],nC_Number[j]))count ++;elsebreak;}if(count>1){flag=1;for(k=0; k<3; k++) printf("%c", nC_Number[i][k]);printf("-");for(k=3; k<7; k++) printf("%c", nC_Number[i][k]);printf(" %d/n", count);}i=j-1;}if(flag==0)printf("No duplicates./n");}return 0;}