代码实现：

在缺失的 n 个观测数据中，有 y 个观测数据是 x+1，其余观测数据都是x

int* missingRolls(int *rolls, int rollsSize, int mean, int n, int *returnSize) {
    int m = rollsSize;
    int sum = mean * (n + m);
    int missingSum = sum;
    for (int i = 0; i < m; i++) {
        missingSum -= rolls[i];
    }
    if (missingSum < n || missingSum > 6 * n) {
        *returnSize = 0;
        return NULL;
    }
    int x = missingSum / n, y = missingSum % n;
    int *res = (int*)malloc(sizeof(int) * n);
    for (int i = 0; i < n; i++) {
        res[i] = x + (i < y ? 1 : 0);
    }
    *returnSize = n;
    return res;
}