帮我出五个C语言关于数组或指针知识点的程序填空题

1. 计算数组元素和

int arr[5] = {1, 2, 3, 4, 5};
int sum = 0;
for (int i = 0; i < 5; i++) {
    sum += _________;
}
printf("数组元素和为：%d", sum);

答案：arr[i]

2. 交换两个变量的值

int a = 5, b = 10;
int temp;
_________ = a;
a = b;
b = temp;
printf("a = %d, b = %d", a, b);

答案：temp = a;

3. 按升序排序数组

int arr[5] = {3, 1, 4, 2, 5};
for (int i = 0; i < 5; i++) {
    for (int j = i + 1; j < 5; j++) {
        if (arr[i] > _________) {
            int temp = arr[i];
            arr[i] = arr[j];
            arr[j] = temp;
        }
    }
}
for (int i = 0; i < 5; i++) {
    printf("%d ", arr[i]);
}

答案：arr[j]

4. 按降序排序数组

int arr[5] = {3, 1, 4, 2, 5};
for (int i = 0; i < 5; i++) {
    for (int j = i + 1; j < 5; j++) {
        if (arr[i] < _________) {
            int temp = arr[i];
            arr[i] = arr[j];
            arr[j] = temp;
        }
    }
}
for (int i = 0; i < 5; i++) {
    printf("%d ", arr[i]);
}

答案：arr[j]

5. 求数组中最大值

int arr[5] = {3, 1, 4, 2, 5};
int max = arr[0];
for (int i = 1; i < 5; i++) {
    if (arr[i] > _________) {
        max = arr[i];
    }
}
printf("数组中最大值为：%d", max);

答案：max