C語言finput這個函數(shù)只會寫入stu[1]，輸入一個覆蓋一個。

ID:881546 · 發(fā)表于 2021-11-25 14:35

還有平均成績的輸出也只能輸出一個，這是什么問題求大佬指點？

#include <stdio.h>
#include <string.h>
#include <stdlib.h> //提供 exit() 函數(shù)支持
#define SIZE 100000
//#include"conio.h"
//聲明函數(shù)原型
void finput(); //存入數(shù)據(jù)
void flist(); //輸出數(shù)據(jù)
void fmax(); //取最大成績
void ftaxis(); //數(shù)據(jù)排序
void stat(); //統(tǒng)計數(shù)據(jù)
//定義結構體
struct student
{
int num; //存放
char name[10]; //定義名字數(shù)組變量
int En; //英語課成績
int Math; //數(shù)學課成績
int C; //計算機語言成績
int Mz; //馬哲成績
int Ei; //電子技術
float ave; //三門課平均成績
} stu[SIZE]; //在定義結構體時同時聲明結構體變量
volatile int length = 0;
int main()
{
int n;
for(;;) //使程序能夠循環(huán)，在循環(huán)內部判斷何時結束
{
printf("\n\n"); //與上次的輸出結果保持間隔，便于美觀
printf(" _________________________________\n");//菜單輸出
printf(" | MENU |\n");
printf(" | 1.輸入成績 |\n");
printf(" | 2.輸出最大成績 |\n");
printf(" | 3.輸出按成績大小排列 |\n");
printf(" | 4.輸入數(shù)字查看人數(shù)占比 |\n");
printf(" | 5. 退出 |\n");
printf(" |_______________________________|\n");
printf(" Please choose your function:(1-5):"); //功能選擇
scanf("%d",&n);
printf("\n");
if(n>0&&n<=8) {
switch(n) {
case 1:
finput();
break;
case 2:
flist();
fmax();
break;
case 3:
ftaxis();
break;
case 4:
stat();
case 5:
printf("\n ~~~~~~~~~~~~~~~~~~~~~~~~~~\n"); //退出提示
printf(" Goodbye! \n");
printf(" ~~~~~~~~~~~~~~~~~~~~~~~~~~\n");
exit(0);//將程序退出
}
} else //沒有按規(guī)范選擇功能，要進行錯誤提示 //錯誤提示
{
printf("\n ~~~~~~~~~~~~~~~~~~~~~~~~~~\n");
printf(" error input! \n");
printf(" ~~~~~~~~~~~~~~~~~~~~~~~~~~\n");
// break; //應該將這一句話去掉才能使在輸錯的情況下也進行菜單循環(huán)
}
}
return 0;
}
//part 1 : 進行信息錄入
void finput()
{
FILE *fp; //聲明指針變量
int i;
fp=fopen("grades","wb"); //首次打開文件，若沒有文件將會自動創(chuàng)建新文件
for(i=0; i<SIZE; i++)
{
printf("1 to continue and 0 to end input: "); //詢問是否繼續(xù)輸入
scanf("%d",&i);
if(i==0)
{
fclose(fp);
return;
}
else {
printf("Please inut your school number, your name,English grade, Math grade, C grade, Mazhe grade, Electronic grade:\n");
scanf("%d%s%d%d%d%d%d",&stu[i].num,stu[i].name,&stu[i].En,&stu[i].Math,&stu[i].C,&stu[i].Mz,&stu[i].Ei);
stu[i].ave=(stu[i].C+stu[i].Math+stu[i].En+stu[i].Mz+stu[i].Ei)/5.0;
fwrite(&stu[i],sizeof(struct student),1,fp);
length++;
}
fclose(fp);
}
}
//part 2: 將結果輸出
void fmax()
{
int res[256];
int max;
int maximum;
size_t i;
for(i = 0; i < length; i++){
res[i] = stu[i].C+stu[i].Math+stu[i].En+stu[i].Mz+stu[i].Ei;
}
printf("%d", length);
max = res[0];
for(i = 0; i < length; i++){
if(res[i] >= max) {
max = res[i];
maximum = i;
}
}
printf("The most niubility student information is:\n");
printf("Student ID\t Name\t English\t Math\t C \t Electronic\t Maze\t \n");
printf("%d\t %s\t %d\t %d\t %d\t %d\t %d\t\n", stu[maximum].num,stu[maximum].name,stu[maximum].En,stu[maximum].Math,stu[maximum].C,stu[maximum].Mz,stu[maximum].Ei);
}
void flist()
{
FILE *fp;
int i;
fp=fopen("grades","rb");
printf("____________________________________________________________________________________________________\n");
printf("| Report |\n");
printf("|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|\n");
printf("| ID | name | English grade | Math grade | Computer grade | Ma zhe | Electron grade | Average |\n");
printf("|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|\n");
for(i=0; fread(&stu[i],sizeof(struct student),1,fp)==1; i++)
printf("|%11d%15s%13d%17d%18d%16d%14d%19.2f\n",stu[i].num,stu[i].name,stu[i].En,stu[i].Math,stu[i].C,stu[i].Mz,stu[i].Ei,stu[i].ave);
/*
此處采用字寬輸入比加空格更好，因為若是使用空格輸入，當學號或者名字前后輸入的長度不一致時，格式會亂掉，導致無法對其格式
*/
printf("|___________________________________________________________________________________________________|\n\n");
fclose(fp);
}//part 3：按平均成績進行排序
void ftaxis()
{
int i,j,n;
FILE *fp;
struct student t;
fp=fopen("grades","rb");
printf("____________________________________________________________________________________________________ \n");
printf("| Report |\n");
printf("|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|\n");
printf("| ID | name | English grade | Math grade | C grade | Ma zhe | Electron grade | Average |\n");
printf("|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|\n");
for(i=0; fread(&stu[i],sizeof(struct student),1,fp)==1; i++)
printf("|%11d%15s%13d%17d%18d%16d%14d%19.2f\n",stu[i].num,stu[i].name,stu[i].En,stu[i].Math,stu[i].C,stu[i].Mz,stu[i].Ei,stu[i].ave);
printf("|___________________________________________________________________________________________________|\n\n");
fclose(fp);
n=i;
for(i=0; i<n; i++)
for(j=i+1; j<n; j++)
if(stu[i].ave<stu[j].ave)
{
t=stu[i];
stu[i]=stu[j];
stu[j]=t;
}
fp=fopen("grades","wb");
printf("\n\n\n");
printf("_____________________________________________________________________________________________________\n");
printf("| Report |\n");
printf("|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|\n");
printf("| ID | name | English grade | Math grade | C grade | Ma zhe | Electron grade | Average |\n");
printf("|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|\n");
for(i=0; i<n; i++)
{
fwrite(&stu[i],sizeof(struct student),1,fp);
printf("|%11d%15s%13d%17d%18d%16d%14d%19.2f\n",stu[i].num,stu[i].name,stu[i].En,stu[i].Math,stu[i].C,stu[i].Mz,stu[i].Ei,stu[i].ave);
}
printf("|___________________________________________________________________________________________________|\n");
fclose(fp);
}
//part 4: 統(tǒng)計指定分數(shù)之上的人數(shù)
void stat()
{
FILE *fp;
int i,flag=0,count=0,b;//flag 用來判斷是否需要進行錯誤提示, count用來統(tǒng)計個數(shù)
float score_;
fp=fopen("grades","rb");
rewind(fp);
printf("Do you want to know the percentage of the total score?\nEnter your number: ");
scanf("%f",&score_);
for(i=0; i<=SIZE; i++)
{
if(score_ < stu[i].ave )
{
count++;
flag=1;
}
}
if(flag == 1)
printf("%d in total above your number\n",count);
if(flag==0)
{
printf("\n ~~~~~~~~~~~~~~~~~~~~~~~~~~\n");
printf(" error input! \n");
printf(" ~~~~~~~~~~~~~~~~~~~~~~~~~~\n");
}
// printf("___________________________________________________________________________________________________________\n\n");
fclose(fp);
}

復制代碼

ID:883242 · 發(fā)表于 2021-11-25 17:44

你讀了一次就把文件關閉了，下次重新打開當然還是第一條記錄。

ID:881546 · 發(fā)表于 2021-11-25 18:40

Hephaestus 發(fā)表于 2021-11-25 17:44
你讀了一次就把文件關閉了，下次重新打開當然還是第一條記錄。

那應該怎么改

ID:139866 · 發(fā)表于 2021-11-30 15:23

好家伙，聲明個變量8000000個字節(jié)

ID:844772 · 發(fā)表于 2021-11-30 15:40

1.fclose(fp); 要放到for循環(huán)之外，否則第一條就關閉的文件指針，就不能繼續(xù)了。
2.你應該使用鏈表結構，而不是定義一個巨大的數(shù)組。
3.你的存儲函數(shù)有問題，沒有考慮插入問題，如果二次運行就會混亂了。
另外，能解釋一下這個程序我們單片機論壇的關系嗎？

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C語言finput這個函數(shù)只會寫入stu[1]，輸入一個覆蓋一個。