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

int main() {

    srand(getpid() ^ time(0)); // set seed
    int h[3]; // heaps
    // initialize heaps
    for (int i=0; i<3; ++i) {
        h[i] = rand() % (10 - 5 + 1) + 5;
    }

    printf("*** Three Heaps ***\n");
    printf("Initial state: %d %d %d\n", h[0], h[1], h[2]);
    printf("Rules: In each turn each player may take one, two, or three\n");
    printf("       sticks from one of the heaps. The player who removes\n");
    printf("       the last sticks wins.\n");
    printf("Do you want to begin? 1 = yes, 0 = no: ");
    int players_turn;
    if (scanf("%d", &players_turn) != 1 ||
      (players_turn != 0 && players_turn != 1)) {
        exit(255);
    }
    while (h[0] > 0 || h[1] > 0 || h[2] > 0) {
        /* print current state */
        printf("Heaps: %d %d %d\n", h[0], h[1], h[2]);

        /* next move: */
        int heap; // select heap
        int quantity; // number of sticks that are to be removed from the heap

        /* get next move */
        if (players_turn) {
            /* read move from our human player */
            do {
                printf("Which heap (1-3)? ");
                if (scanf("%d", &heap) != 1) exit(255);
            } while (heap < 1 || heap > 3);
            do {
                printf("How many? ");
                if (scanf("%d", &quantity) != 1) exit(255);
            } while (quantity < 1 || quantity > 3);

            if ((heap == 1 && quantity > h[0])
                    || (heap == 2 && quantity > h[1])
                    || (heap == 3 && quantity > h[2])) {
                printf("Not that many sticks left on heap %d\n", heap);
                continue;
            }
            players_turn = 0; // computer is next
        }
        else { // computer's turn
            /* "strategy": always pick maximum quantity from biggest heap*/
            int max_id = 0;
            for (int i = 0; i < 3; ++i) {
                if (h[i] > h[max_id]) {
                    max_id = i;
                }
            }
            if (h[max_id] < 3) {
                quantity = h[max_id]; // take complete heap
            }
            else quantity = 3; // take 3
            heap = max_id +1;
            players_turn = 1; // computer finishes, human player is next
        }
        /* execute move */
        printf("Taking %d sticks from heap %d\n", quantity, heap);
        h[heap-1] -= quantity;
    }
    if (players_turn) {
        printf("You lose!\n");
    } else {
        printf("Congratulations, you've won!\n");
    }
}