按字母顺序或降序对多个数组进行排序

Question

该程序应该接受学生的姓氏 (LN)、名字 (FN)、中间名首字母 (MI)、地址 (ADD)、第一、第二、第三和第四季度的成绩（FIR、SEC、THR , FTH)，计算四个输入成绩的平均值，并按字母顺序（姓氏）或降序（平均值）显示所有信息。

它应该是这样的：

.
.    Last name:                 First name:                 Middle Intial:     Address:
.
.                   First Quarter grades:
.                   Second Quarter grades:
.                   Third Quarter grades:
.                   Fourth Quarter grades:
.                   Average:
.
.    Which way do you want to arrange the names? Enter A to alphabetize or B to arrange in descending order by grade.

之后，它应该清除屏幕并只显示名称。

.
.    List:
.
.    Apple, Johnny K. from Kansas 89 91 89 91 90.0
.    Graham, Crackers L. from N.Y. 79 81 79 81 80.0
.

实际上应该招收 90 名学生，但我设置了 3 作为测试人数。

输入所有数据后，会提示“segmentation fault”。

谁能告诉我我做错了什么？我应该在最后一部分使用 puts 而不是 printf 吗？如果是这样，我该怎么做？

#include <stdio.h>
#include <string.h>
#include <conio.h>

int main()
{
int a=0, SW=1, x, y, i, j, FIR[100], SEC[100], THR[100], FTH[100], AVE[100], sum=0, temp2[100];
char LN[15][90], FN[15][90], MI[5][90], ADD[50][90], OPT, temp1[50];
while(SW)
{
    clrscr();
    sum=0;

    gotoxy(10,2);
    printf("Family name: ");
    gotoxy(35,2);
    printf("First name: ");
    gotoxy(60,2);
    printf("Middle initial: ");
    gotoxy(80,2);
    printf("Address: ");
    gotoxy(25,4);
    printf("1st Quarter Grade: ");
    gotoxy(25,5);
    printf("2nd Quarter Grade: ");
    gotoxy(25,6);
    printf("3rd Quarter Grade: ");
    gotoxy(25,7);
    printf("4th Quarter Grade: ");
    gotoxy(25,8);
    printf("Average: ");
    gotoxy(23,2);
    fgets(LN[a],15,stdin);
    gotoxy(47,2);
    fgets(FN[a],15,stdin);
    gotoxy(76,2);
    fgets(MI[a],15,stdin);
    gotoxy(89,2);
    fgets(ADD[a],15,stdin);
    gotoxy(44,4); 
    scanf("%d",&FIR[a]);
    sum+=FIR[a];
    gotoxy(44,5);
    scanf("%d",&SEC[a]);
    sum+=SEC[a];
    gotoxy(44,6);
    scanf("%d",&THR[a]);
    sum+=THR[a];
    gotoxy(44,7);
    scanf("%d",&FTH[a]);
    sum+=FTH[a];
    AVE[a]=(float)sum/4;
    gotoxy(34,8);
    printf("%d",AVE[a]);
    a++;
    if(a==3)
        SW=0;
    getch();    
}        
gotoxy(10,10);
printf("Which way do you want to arrange the names? Enter A to alphabetize or B to arrange in descending order by grade. ");
gotoxy(10,11);
scanf("%c",&OPT);
if(OPT=='A' || OPT=='a')
{
    for(x=0;x<=2;x++){
        for(y=x+1;y<=2;y++){
            if(strcmp(LN[x],LN[y])>0){
                strcpy(temp1, LN[x]);
                strcpy(LN[x], LN[y]);
                strcpy(LN[y], temp1);
                strcpy(temp1, FN[x]);
                strcpy(FN[x], FN[y]);
                strcpy(FN[y], temp1);
                strcpy(temp1, MI[x]);
                strcpy(MI[x], MI[y]);
                strcpy(MI[y], temp1);
                strcpy(temp1, ADD[x]);
                strcpy(ADD[x], ADD[y]);
                strcpy(ADD[y], temp1);
                strcpy(temp2, FIR[x]);
                strcpy(FIR[x], FIR[y]);
                strcpy(FIR[y], temp2);
                strcpy(temp2, SEC[x]);
                strcpy(SEC[x], SEC[y]);
                strcpy(SEC[y], temp2);
                strcpy(temp2, THR[x]);
                strcpy(THR[x], THR[y]);
                strcpy(THR[y], temp2);
                strcpy(temp2, FTH[x]);
                strcpy(FTH[x], FTH[y]);
                strcpy(FTH[y], temp2);
                strcpy(temp2, AVE[x]);
                strcpy(AVE[x], AVE[y]);
                strcpy(AVE[y], temp2);
            }
        }
    }
}    
else
{
    for(x=0;x<=2;x++){
        for(y=x+1;x<=2;x++){
            if(AVE[x]<AVE[y]){
                strcpy(temp1, LN[x]);
                strcpy(LN[x], LN[y]);
                strcpy(LN[y], temp1);
                strcpy(temp1, FN[x]);
                strcpy(FN[x], FN[y]);
                strcpy(FN[y], temp1);
                strcpy(temp1, MI[x]);
                strcpy(MI[x], MI[y]);
                strcpy(MI[y], temp1);
                strcpy(temp1, ADD[x]);
                strcpy(ADD[x], ADD[y]);
                strcpy(ADD[y], temp1);
                strcpy(temp2, FIR[x]);
                strcpy(FIR[x], FIR[y]);
                strcpy(FIR[y], temp2);
                strcpy(temp2, SEC[x]);
                strcpy(SEC[x], SEC[y]);
                strcpy(SEC[y], temp2);
                strcpy(temp2, THR[x]);
                strcpy(THR[x], THR[y]);
                strcpy(THR[y], temp2);
                strcpy(temp2, FTH[x]);
                strcpy(FTH[x], FTH[y]);
                strcpy(FTH[y], temp2);
                strcpy(temp2, AVE[x]);
                strcpy(AVE[x], AVE[y]);
                strcpy(AVE[y], temp2);
            }
        }
    }
}
gotoxy(10,15);
printf("List: ");
for(j=17;j<=19;j++){
    for(x=0;x<=2;x++){
    i=10;
    gotoxy(i,j);
    printf("%s,%s %s",LN[x],FN[x],MI[x]);
    i+=40;
    gotoxy(i,j);
    printf("%f",FIR[x]);
    i+=5;
    gotoxy(i,j);
    printf("%f",SEC[x]);
    i+=5;
    gotoxy(i,j);
    printf("%f",THR[x]);
    i+=5;
    gotoxy(i,j);
    printf("%f",FTH[x]);
    i+=5;
    gotoxy(i,j);
    printf("%f",AVE[x]);
    i+=5;
    gotoxy(i,j);
    printf("from %s",ADD[x]);
    }
}

}

编辑：我不知道我在做什么。我只是想通过 8 年级的计算机科学。

Answer 1

该程序应该接受学生的姓氏 (LN)、名字 (FN)、中间名首字母 (MI)、地址 (ADD)、第一、第二、第三和第四季度的成绩（FIR、SEC、THR , FTH)，计算四个输入成绩的平均值，并按字母顺序（姓氏）或降序（平均值）显示所有信息。

您当前使用的设计无法维护且杂乱无章。听起来您需要使用结构来代表学生：

#define MAX_LNAME    80
#define MAX_FNAME    32
#define MAX_ADDRESS  128

typedef struct {
    char lname[MAX_LNAME];
    char fname[MAX_FNAME];
    char address[MAX_ADDRESS];
    double fir, sec, thr, fth;
} student;

然后是一些将操作或创建student 结构的函数

student mkstudent(char *lname, char *fname, char *address, 
                  double fir, double sec, double thr, double fth)
{
    student ret;

    strcpy(ret.lname, lname);
    strcpy(ret.fname, fname);
    strcpy(ret.address, address);
    ret.fir = fir; ret.sec = sec; ret.thr = thr; ret.fth = fth;

    return ret;
}
double getAve(const student *s)
{
    return (s->fir + s->sec + s->thr + s->fth) / 4.;
}
void print(const student *s)
{
    printf("%s, %s from %s: %lf %lf %lf %lf %lf\n", s->lname, s->fname, 
               s->address, s->fir, s->sec, s->thr, s->fth, getAve(s));
}

您的程序要求对学生进行排序，因此您需要使用qsort（来自<stdlib.h>）

int sortAlpha(const void *a, const void *b)
{
    return strcmp( ((const student *) a)->lname, 
                   ((const student *) b)->lname );
}

int sortAves(const void *pa, const void *pb)
{
    const student *a = (const student *) pa;
    const student *b = (const student *) pb;

    double aAve = getAve(a), bAve = getAve(b);

    if (aAve == bAve) return 0;
    if (aAve > bAve) return -1;
    if (aAve < bAve) return 1;
}

#define SORT_LNAME 0    /* sort by last name */
#define SORT_AVES  1    /* sort by average, in descending order */

/* howSort will be one of the two macros defined above */
void sort(students *roster, size_t n, int howSort)
{
    if (howSort == SORT_LNAME)
        qsort(roster, n, sizeof *roster, sortAlpha);
    else (howSort == SORT_AVES)
        qsort(roster, n, sizeof *roster, sortAves);
}

现在你已经编写了这个接口，你可以通过调用上面实现的各种例程来编写你的主函数

int main()
{
    /* array of student structures, possibly read them in from a file, 
       possibly print them, then ask user how to sort, etc. */
}