Question

我在学校学习C ++课程，并决定自己学习C语言课程。试图制作一个小程序，计算我班级的平均成绩，并显示学生的字母等级。当我输入学生的分数时，我输入4个值并显示分段错误后代码停止。我很确定这是原因，但不确定如何修复它。我将不胜感激任何帮助。

#include <stdio.h>
#define _CRT_SECURE_NO_WARNINGS

double Average(double * scores, int N) {
    int i;
    double total = 0;
    for (i = 0; i < N; i++) {
        total = total + scores[i];
    }
    return total / N;
}

int Agrade(double * scores, int N) {
    int i;
    int count = 0;
    for (i = 0; i < N; i++) {
        if (scores[i] >= 90 && scores[i] <= 100) count++;
    }
    return count;
}

int Bgrade(double * scores, int N) {
    int i;
    int count = 0;
    for (i = 0; i < N; i++) {
        if (scores[i] >= 80 && scores[i] < 90) count++;
    }
    return count;
}

int Cgrade(double * scores, int N) {
    int i;
    int count = 0;
    for (i = 0; i < N; i++) {
        if (scores[i] >= 70 && scores[i] < 80) count++;
    }
    return count;
}

int Dgrade(double * scores, int N) {
    int i;
    int count = 0;
    for (i = 0; i < N; i++) {
        if (scores[i] >= 60 && scores[i] < 70) count++;
    }
    return count;
}
int Fgrade(double * scores, int N) {
    int i;
    int count = 0;
    for (i = 0; i < N; i++) {
        if (scores[i] < 60) count++;
    }
    return count;
}

int main() {
    int i;
    int N;
    double * scores;

    printf("How many test scores? ");
    scanf("%d", & N);
    if (N < 1) {
        printf("Invalid input. try again");
    } else if (N > 25) {
        printf("1-25 only.");
    } else if (N > 0 && N < 25) {
        printf("Total number of test is: %d\n", N);
    }

    double * scores = malloc(N * sizeof(double)); /* allocate the memory for N students */
    for (i = 0; i < N; i++) {
        printf("Enter the score of students: ");
        scanf("%lf", & scores[i]);
    }
    double averagescore = Average(scores, N);
    int scoreAcount = Agrade(scores, N);
    int scoreBcount = Bgrade(scores, N);
    int scoreCcount = Cgrade(scores, N);
    int scoreDcount = Dgrade(scores, N);
    int scoreFcount = Fgrade(scores, N);
    printf("The average test score : %lf", averagescore);
    printf("The number of A grades : %d\n", scoreAcount);
    printf("The number of B grades : %d\n", scoreBcount);
    printf("The number of C grades : %d\n", scoreCcount);
    printf("The number of D grades : %d\n", scoreDcount);
    printf("The number of F grades : %d\n", scoreFcount);

    return 0;
}

Answer 1

请参阅以下代码的代码块。

for(i = 0; i < sizeof(N); i++) { /* sizeof(N) is wrong */
    printf("Enter the score of students: ");
    scanf("%d",&N);/* putting data into N ? its wrong */
}
double averagescore = Average(scores, N); /* calling averagescore() with scores which is uninitialized & contain nothing ? */

应该是

double *scores = malloc(N * sizeof(double));/* allocate the memory for N students */
for(i = 0; i < N; i++) {
    printf("Enter the score of students: ");
    scanf("%lf",&scores[i]);
}

这是工作中的

 int main(){
            int i;
            int N;
            printf("How many test scores? "); //Number of students. Trying to calculate up to 25 students
            scanf("%d",&N);
            if(N<1){
                    printf("Invalid input. try again");
            }
            else if(N>25)
            {
                    printf("1-25 only.");
            }
            else if(N>0 && N<25){
                    printf("Total number of test is: %d\n", N);
            }
            double *scores = malloc(N * sizeof(double));/* allocate the memory for N students */
            for(i = 0; i < N; i++) {
                    printf("Enter the score of students: ");
                    scanf("%lf",&scores[i]);
            }
            double averagescore = Average(scores, N);
            int scoreAcount = Agrade(scores, N);
            int scoreBcount = Bgrade(scores, N);
            int scoreCcount = Cgrade(scores, N);
            int scoreDcount = Dgrade(scores, N);
            int scoreFcount = Fgrade(scores, N);
            printf("The average test score : %f\n", averagescore);
            printf("The number of A grades : %d\n", scoreAcount);
            printf("The number of B grades : %d\n", scoreBcount);
            printf("The number of C grades : %d\n", scoreCcount);
            printf("The number of D grades : %d\n", scoreDcount);
            printf("The number of F grades : %d\n", scoreFcount);
            return 0;
  }

了解如何调试小代码。

Answer 2

函数sizeof返回变量＆＃39; N＆＃39;的字节数。包含的内容。你不想要那个！您应该将sizeof（N）替换为N，以便从输入的N个数字中读取。你也应该在循环中检查你的代码，因为它不对！

Answer 3

sizeof(N)

这是错误的。 N已经是一个整数，所以要求大小是没用的，除非你试图分配一些内存来保存一个int，你不是。

C使用指针评分测试分数 - 4个条目后的段错误

3 个答案: