c语音解答，可以有偿

Question

Answer 1

你题目的解答代码如下：（如有帮助，望采纳！谢谢! 点击我这个回答右上方的【采纳】按钮）

#include<stdio.h>

int main() {
    int n;
    FILE *fp;
    char c;

    printf("---------------菜单-------------\n");
    printf("a)找到data.txt中的最大数字\n");
    printf("b)计算data.txt中所有正数的平均值\n");
    printf("请选择a或b：");
    c = getchar();
    if (c=='a' || c=='A')
    {
        int max;
        fp = fopen("data.txt", "r");
        fscanf(fp, "%d", &max);
        while (fscanf(fp, "%d", &n)>0)
        {
            if (n>max)
                max = n;
        }
        fclose(fp);
        printf("最大数字:%d",max);
    }
    else
    {
        float sum=0,avg;
        int i=0;
        fp = fopen("data.txt", "r");
        while (fscanf(fp, "%d", &n)>0)
        {
            if (n>0) {
                sum += n;
                i++;
            }
        }
        avg = sum/i;
        fclose(fp);
        printf("所有正数的平均值%.3f",avg);
    }

    return 0;
}