PATA -1006 Sign In and Sign Out

#include<stdio.h>
#include<string.h>
using namespace std;
struct t{
    int h,m,s;
    t(){h=0;m=0;s=0;}
};
struct t tranvert(char[]);
int comparet(char [],char []);
int main(){
    int M;
    scanf("%d",&M);
    char n[20],timein[20],timeout[20];
    char resnin[20],resnout[20];
    char restimein[20],restimeout[20];
    scanf("%s %s %s",n,timein,timeout);
    strcpy(resnin,n);
    strcpy(resnout,n);
    strcpy(restimein,timein);
    strcpy(restimeout,timeout);
    for(int i=1;i<M;i++){
        scanf("%s %s %s",n,timein,timeout);
        if(comparet(timein,restimein)<0){
            strcpy(resnin,n);
            strcpy(restimein,timein);
        }
        if(comparet(timeout,restimeout)>0){
            strcpy(resnout,n);
            strcpy(restimeout,timeout);
        }
    }
    
    printf("%s %s",resnin,resnout);
    return 0;
}
struct t tranvert(char a[20]){
    struct t t1;
    t1.h = (a[0]-'0')* 10 + (a[1]-'0');
    t1.m = (a[3]-'0')* 10 + (a[4]-'0');
    t1.s = (a[6]-'0') * 10 + (a[7]-'0');
    return t1;
    
}
int comparet(char t1[20],char t2[20]){
    struct t  tt1,tt2;
    tt1 = tranvert(t1);
    tt2 = tranvert(t2);
    if(tt1.h>tt2.h) return 1;
    else if(tt1.h==tt2.h){
        if(tt1.m==tt2.m){
            if(tt1.s==tt2.s) return 0;
            else if(tt1.s>tt2.s) return 1;
            else return -1;
        }else if(tt1.m>tt2.m) return 1;
        else return -1;
    }
    else return -1;
}