zoj 1315 Excuses, Excuses!

#include<stdio.h>#include<string.h>struct Node{    char key[21];}node[21];struct Ans{    char ss[100];    int count;}ans[21];void Str2str(char ss[]){    for (int i=0;ss[i];i++)    {        if(ss[i]>='A' && ss[i]<='Z') ss[i]+=32;    }}int main(){    int n,k,i,j,t;    char word[100];    int tes=1;    while(scanf("%d%d",&n,&k)!=EOF)    {        int max=0;        getchar();        memset(ans,0,sizeof(ans));        for (i=0;i<n;i++)        { gets(node[i].key);        }        int cas=0;        int flag=0;        for (i=0;i<k;i++)        { gets(ans[i].ss); int leng=strlen(ans[i].ss); for (j=0;j<=leng;j++) {     if((ans[i].ss[j]<'A' || ans[i].ss[j]>'z' || (ans[i].ss[j]>'Z' && ans[i].ss[j]<'a') || j==leng) && flag==1)     {          flag=0;         word[cas]='';         cas=0; Str2str(word);         for (t=0;t<n;t++)         {  if(!strcmp(word,node[t].key)) ans[i].count++;         }      }     else { word[cas++]=ans[i].ss[j]; flag=1; }         } if(ans[i].count>max) max=ans[i].count;        }        printf("Excuse Set #%dn",tes++);        for (i=0;i<k;i++)        { if(ans[i].count==max) printf("%sn",ans[i].ss);        }        printf("n");    }    return 0;}