Advent of Code 2018 day 9 in C

09.c

#include <stdio.h>
#include <stdlib.h>

int Solve(int players, int marbles) {
    int *scores = calloc(players, sizeof(int));
    int *prev = calloc(marbles, sizeof(int));
    int *next = calloc(marbles, sizeof(int));
    int i = 0;
    for (int j = 1; j < marbles; ++j) {
        if (j%23 != 0) {
            i = next[i];
            int k = next[i];
            next[i] = j;
            prev[j] = i;
            next[j] = k;
            prev[k] = j;
            i = j;
        } else {
            for (int n = 0; n < 7; ++n)  {
                i = prev[i];
            }
            int player = (j - 1)%players;
            scores[player] += i + j;
            int h = prev[i];
            i = next[i];
            next[h] = i;
            prev[i] = h;
        }
    }
    int max_score = 0;
    for (int i = 0; i < players; ++i) {
        if (scores[i] > max_score) {
            max_score = scores[i];
        }
    }
    free(scores);
    free(prev);
    free(next);
    return max_score;
}

int main() {
    int players;
    int last_marble;
    if (scanf("%d players; last marble is worth %d points", &players, &last_marble) == 2) {
        printf("%d %d\n", players, last_marble);
        printf("%d\n", Solve(players, last_marble + 1));
        printf("%d\n", Solve(players, (last_marble * 100) + 1));
    }
    return 0;
}