PAT/PATAdvanced/1012.c

#include <stdio.h>

typedef struct Student{ int ID, score[4]; } Student;

int main()
{
	/* scores array stores the number of students of any score */
	int N, M, ID, scores[4][102] = {{0}};

	/* Setting a score of 101 is to make it easy to calculate rank */
	scores[0][101] = scores[1][101] = scores[2][101] = scores[3][101] = 1;
	Student students[2000];

	scanf("%d %d", &N, &M);
	for (int i = 0; i < N; i++) {   /* record all the scores for every student: A, C, M, E */
		Student *s = students + i;
		scanf("%d %d %d %d", &s->ID, &s->score[1], &s->score[2], &s->score[3]);
		s->score[0] = (s->score[1] + s->score[2] + s->score[3] + 1) / 3;
		for (int j = 0; j < 4; j++)                         /* +1 for rounding */
			scores[j][s->score[j]]++;       /* record how many got this score */
	}

	for (int i = 0; i < M; i++) {
		int max = 3, ranks[4] = {0}, stu;

		scanf("%d", &ID);
		for (stu = 0; stu < N && students[stu].ID != ID; stu++) ;      /* find */
		if (stu == N) { puts("N/A"); continue;}

		/* calculate the rank: sum the counts from score + 1 to 101 */
		for (int j = 3; j >= 0; j--) {
			/* e.g. score 100 will have rank 1, since scores[101] is 1 */
			for (int score = 100; score >= students[stu].score[j]; score--)
				ranks[j] += scores[j][score + 1];
			if (ranks[j] <= ranks[max]) /* The best rank with highest priority */
				max = j;
		}
		printf("%d %c\n", ranks[max], "ACME"[max]);
	}
}