Language: C

#include <stdio.h>

float abs(float a){ /*ª0ÌêA-0Æ\¦³êé±Æª éÌÅA³âè³ÌlðÔ·âÎlÖð­*/
	if(a >= 0){
		return (a);
	}
	else{
		return (-1 * a);
	}
}

int main(void) /*±±©çCÖ*/
{
	int hh[100]; /*Ô[0]`Ô[99]Ìüêq*/
	int mm[100]; /*ª[0]`ª[99]Ìüêq*/
	int MM[100]; /*ñiªj[0]`ñiªj[99]Ìüêq*/
	int ds; /*f[^ZbgÌ*/
	int i; /*for¶ðñ·½ßÌÏ*/
	float j[2];
	float k[2];
	float l[2];
	
	scanf("%d", &ds) ; /*f[^ZbgÌðmF*/
	
	while(ds != 0){
		j[0] = 0; /*¢ë¢ëÆú».*/
		j[1] = 0; /*j¨ÉÎ*/
		k[0] = 0;
		k[1] = 0; /*k¨[ûÉÎ*/
		l[0] = 0;
		l[1] = 0; /*l¨[éÉÎ*/
		for (i = 0; i < ds; i++){ /*i+1ÔÚÌÔAªAñ(ª)ðüÍB*/
			scanf("%d%*c%d%d",&hh[i], &mm[i], &MM[i]);
			
			if (11 <= hh[i] && hh[i] <= 14){ /*àµAÔª11(00ª)©ç14(59ª)ÈçÎ*/
				j[0]++; /*j[0],j[1]É1ð«·BÅIIÉÍAj[1]/[j[0](=)ðoÍ·é.ÈãA»ê¼êð0A1ÆæÔB*/
				j[1]++;
				if(mm[i] >= 52 &&  MM[i] <= 08){ /*àµAª45ª`59ªÌÔA©ÂAñª{100ª`{115ªÌÔÈçA*/
					MM[i] += 60; /*ñÔÉ60ð«µAø«ZÌÊª³ÉÈéæ¤ÉHv·é.¨±ñÈÉÍ¢çÈ¢H*/
				}
				if (MM[i] - mm[i] > 8){ /*àµAñ \ `[ ª Wªæèå«¯êÎ*/
					j[1]--; /*[1]iªqj©ç1ðø­BÈºA[ûA[éà¯lÌð·é.*/
				}
			}
			else if (18 <= hh[i] && hh[i] <= 20){
				k[0]++;
				k[1]++;
				if(mm[i] >= 52 && MM[i] <= 08 ){
					MM[i] += 60;
				}
				if (MM[i] - mm[i] > 8){
					k[1]--;
				}
			}
		
		 if ((21 <= hh[i] && hh[i] <= 23)||hh[i] == 00 || hh[i] == 01){
				l[0]++;
				l[1]++;
				if(mm[i] >= 52 && MM[i] <= 08){
					MM[i] += 60;
				}
				if (MM[i] - mm[i] > 8){
					l[1]--;
				}
		 	}
		}
		
		/*02`10A15`17ÌÍµÈ¢B*/
			
		printf("lunch ");
		if(j[0] == 0){ /*àµA0ª0ÈçÎ(É`[ªÈ¯êÎ)*/
			printf("no guest\n"); /*no guestÆoÍ·é.*/
		}
		else{
			printf("%.0f\n",abs((j[1] / j[0] - 0.005)) * 100); /*¬_ÈºØèÌÄÌ½ßA0.005ðø¢Ä¨­*/
		}
		/*ÈºA[A[éà¯lÉ·é*/
		printf("dinner ");
		if(k[0] == 0){
			printf("no guest\n");
		}
		else{
			printf("%.0f\n", abs((k[1] / k[0] - 0.005)) * 100 );
		}
		
		printf("midnight ");
		if(l[0] == 0){
			printf("no guest\n");
		}
		else{
			printf("%.0f\n", abs((l[1] / l[0] - 0.005)) * 100);
		}
		
		scanf("%d", &ds);
	}
	return (0);
}

Compiler output:
main.c:3:7: warning: conflicting types for built-in function 'abs'; expected 'int(int)' [-Wbuiltin-declaration-mismatch]
    3 | float abs(float a){ /*ª0ÌêA-0Æ\¦³êé±Æª éÌÅA³âè³ÌlðÔ·âÎlÖð­*/
      |       ^~~
main.c:2:1: note: 'abs' is declared in header '<stdlib.h>'
    1 | #include <stdio.h>
  +++ |+#include <stdlib.h>
    2 | 
main.c: In function 'main':
main.c:38:61: error: invalid digit "8" in octal constant
   38 |                                 if(mm[i] >= 52 &&  MM[i] <= 08){ /*àµAª45ª`59ªÌÔA©ÂAñª{100ª`{115ªÌÔÈçA*/
      |                                                             ^~
main.c:48:60: error: invalid digit "8" in octal constant
   48 |                                 if(mm[i] >= 52 && MM[i] <= 08 ){
      |                                                            ^~
main.c:59:60: error: invalid digit "8" in octal constant
   59 |                                 if(mm[i] >= 52 && MM[i] <= 08){
      |                                                            ^~