浙大PAT 1006题 1006. Sign In and Sign Out

#include<stdio.h>
#include<string.h>
int main(){
char lkman[20],unlkman[20];
char id[20],in[20],out[20];
char fst[20]={"24:00:00"},last[20]={"00:00:00"};
int i,j,n;
scanf("%d",&n);
for(i=0;i<n;i++){
scanf("%s %s %s",id,in,out);
if(strcmp(in,fst)<0){
strcpy(fst,in);
strcpy(unlkman,id);
}
if(strcmp(out,last)>0){
strcpy(last,out);
strcpy(lkman,id);
}
}
printf("%s %s\n",unlkman,lkman);
return 0;
}