指標_最後的元素

int extractMax(int* stone, int stoneSize);
int insert(int* stone, int stoneSize);
int lastStoneWeight(int* stones, int stonesSize);


int extractMax(int* stone, int stoneSize) {
    int max = 0;
    int index = 0;
    for (int i = 0; i < stoneSize; i++) {
        if (max < stone[i]) {
            max = stone[i];
            index = i;
        }
    }

    return index;
}

int insert(int* stone, int stoneSize) {
    int x = 0, y = 0;
    int ix = 0, iy = 0;
    while (y>=0) {
        iy = extractMax(stone, stoneSize);
        if (stone[iy] != -1) {
            y = stone[iy];
            stone[iy] = -1;
            ix = extractMax(stone, stoneSize);
            if (stone[ix] == -1) {
                return y;
            }
            else {
                x = stone[ix];
                stone[ix] = -1;
                if (x != y) {
                    stone[iy] = y - x;
                }
            }
        }
        else {
            return 0;
        }
    }

}

int lastStoneWeight(int* stones, int stonesSize) {
    return insert(stones, stonesSize);
}


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

int main() {
    int n = 0;
    int ans;
    scanf("%d", &n);
    int* a = (int*)malloc(n * sizeof(int));

    for (int i = 0; i < n; i++) {
        scanf("%d", &a[i]);
    }
    ans = lastStoneWeight(a, n);
    printf("%d", ans);
    free(a);
    return 0;
}