用语言通过键盘连续输入学生成绩。当输入-1时结束输入计算平均成绩并输出计算结果。分别采用while或do……while循环结构实现

使用while循环结构实现：

#include <iostream>
using namespace std;

int main() {
    int score, sum = 0, count = 0;
    while (true) {
        cin >> score;
        if (score == -1) {
            break;
        }
        sum += score;
        count++;
    }
    if (count == 0) {
        cout << "没有输入成绩" << endl;
    } else {
        double average = static_cast<double>(sum) / count;
        cout << "平均成绩为：" << average << endl;
    }
    return 0;
}

使用do……while循环结构实现：

#include <iostream>
using namespace std;

int main() {
    int score, sum = 0, count = 0;
    do {
        cin >> score;
        if (score != -1) {
            sum += score;
            count++;
        }
    } while (score != -1);
    if (count == 0) {
        cout << "没有输入成绩" << endl;
    } else {
        double average = static_cast<double>(sum) / count;
        cout << "平均成绩为：" << average << endl;
    }
    return 0;
}