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C程序设计 （第四版） 谭浩强 习题7.14
习题 7.14 输入10个学生5门课的成绩，分别用函数实现下列功能：
1. 计算每个学生的平均分；
2. 计算每门课的平均分；
3. 找出所有50个分数中最高的分数所对应的学生和课程；
4. 计算平均分方差：
σ
=
1
n
∑
x
i
2
−
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∑
x
i
n
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2
\sigma=\frac{1}{n}\sum x_i^2-\Bigg(\frac{\sum x_i}{n}\Bigg)^2
σ=n1∑xi2−(n∑xi)2
其中，
x
i
x_i
xi为某一学生的平均分。
IDE工具：VS2010
Note: 使用不同的IDE工具可能有部分差异。
代码块
方法1：使用数组
#include
#include
void inputScore(float stuScore[][5], int stu, int course){
printf("Enter the scores of %d students in %d courses:\n", stu, course);
for(int i = 0; i
printf("Enter No.%d course score: ", j+1);
scanf("%f", &stuScore[i][j]);
while(stuScore[i][j] 100){
printf("Score Error! Retry!\nEnter No.%d course score: ", j+1);
scanf("%f", &stuScore[i][j]);
}
}
}
printf("\n");
}
void stuScoreAverage(float stuScore[][5], int stu, int course, float *stuAver){
float sum = 0.0;
int k = 0;
for(int i = 0; i
sum += stuScore[i][j];
}
stuAver[k++] = sum / course;
printf("The average score of No.%d student is %.2f\n", i+1, sum/course);
sum = 0.0;
}
printf("\n");
}
void courseAverage(float stuScore[][5], int stu, int course){
float sum = 0.0;
for(int i = 0; i
sum += stuScore[j][i];
}
printf("The average score of No.%d course is %.2f\n", i+1, sum/stu);
sum = 0.0;
}
printf("\n");
}
void highestScore(float stuScore[][5], int stu, int course){
float highScore = stuScore[0][0];
int highStu, highCourse;
for(int i = 0; i
if(stuScore[i][j] > highScore){
highScore = stuScore[i][j];
highStu = i + 1;
highCourse= j + 1;
}
}
}
printf("The highest score is %.2f, No.%d Student, No.%d Course\n\n", highScore, highStu, highCourse);
}
void meanVariance(float stuScore[][5], int stu, int course, float *stuAver){
float sum1 = 0.0;
float sum2 = 0.0;
for(int i = 0; i
float stuScore[10][5];
float stuAver[10];
inputScore(stuScore, 10, 5);
stuScoreAverage(stuScore, 10, 5, stuAver);
courseAverage(stuScore, 10, 5);
highestScore(stuScore, 10, 5);
meanVariance(stuScore, 10, 5, stuAver);
system("pause");
return 0;
}
方法2：使用指针、函数指针、动态分配内存
#include
#include
#define S 10 //定义学生数
#define C 5 //定义课程数
//初始化参数
void initialStuScore(float ***stuScore, int stu, int course, float **stuAver){
*stuScore = (float**)malloc(stu * sizeof(float*));
for(int i = 0; i
printf("Enter the scores of %d students in %d courses:\n", stu, course);
for(int i = 0; i
printf("Enter No.%d course score: ", j+1);
scanf("%f", &stuScore[i][j]);
//成绩不合理报错，重新输入
while(stuScore[i][j] 100){
printf("Score Error! Retry!\nEnter No.%d course score: ", j+1);
scanf("%f", &stuScore[i][j]);
}
}
}
printf("\n");
}
void stuScoreAverage(float **stuScore, int stu, int course, float *stuAver){
float sum = 0.0;
int k = 0;
for(int i = 0; i
sum += stuScore[i][j];
}
stuAver[k++] = sum / course;
printf("The average score of No.%d student is %.2f\n", i+1, sum/course);
sum = 0.0;
}
printf("\n");
}
void courseAverage(float **stuScore, int stu, int course, float *stuAver){
float sum = 0.0;
for(int i = 0; i
sum += stuScore[j][i];
}
printf("The average score of No.%d course is %.2f\n", i+1, sum/stu);
sum = 0.0;
}
printf("\n");
}
void highestScore(float **stuScore, int stu, int course, float *stuAver){
float highScore = stuScore[0][0];
int highStu, highCourse;
for(int i = 0; i
if(stuScore[i][j] > highScore){
highScore = stuScore[i][j];
highStu = i + 1;
highCourse= j + 1;
}
}
}
printf("The highest score is %.2f, No.%d Student, No.%d Course\n\n", highScore, highStu, highCourse);
}
void meanVariance(float **stuScore, int stu, int course, float *stuAver){
float sum1 = 0.0;
float sum2 = 0.0;
for(int i = 0; i
for(int i = 0; i
for(int i = 0; i
float **stuScore = NULL;
float *stuAver = NULL;
void (*fun[4])(float**, int, int, float*) = {stuScoreAverage, courseAverage, highestScore, meanVariance};
initialStuScore(&stuScore, S, C, &stuAver);
inputScore(stuScore, S, C);
function(stuScore, S, C, stuAver, fun);
freeStuScore(&stuScore, S, C, &stuAver);
system("pause");
return 0;
}
方法3：使用结构体
#include
#include
#define S 10
#define C 5
struct Student{
float score[C];
void inputScore(int s, int c);
float courseAverage(int c);
float highestScore(int c);
int courseHighScore;
};
void Student::inputScore(int s, int c){
printf("Enter No.%d student scores in %d courses:\n", s, c);
for(int i = 0; i
printf("Score Error! Retry!\nEnter No.%d course score: ", i+1);
scanf("%f", &score[i]);
}
}
printf("\n");
}
float Student::courseAverage(int c){
float sum = 0.0;
for(int i = 0; i
float high = 0;
for(int i = 0; i
high = score[i];
courseHighScore = i + 1;
}
}
return high;
}
void initialStu(Student **stu, int s){
*stu = (Student*)malloc(s * sizeof(Student));
}
void inputStu(Student *stu, int s, int c){
printf("Enter the scores of %d students in %d courses:\n", s, c);
for(int i = 0; i
for(int i = 0; i
float sum = 0.0;
for(int i = 0; i
sum += stu[j].score[i];
}
printf("The average score of No.%d course is %.2f\n", i+1, sum/s);
}
printf("\n");
}
void highestScore(Student *stu, int s, int c){
float high = stu[0].highestScore(c);
int n;
for(int i = 0; i
high = stu[i].highestScore(c);
n = i;
}
}
printf("The highest score is %.2f, No.%d student, No.%d Course\n\n", high, n+1, stu[n].courseHighScore);
}
void meanVariance(Student *stu, int s, int c){
float sum1 = 0.0;
float sum2 = 0.0;
for(int i = 0; i
for(int i = 0; i
free(*stu);
}
int main(){
Student *stu = NULL;
void (*fun[5])(Student*, int, int) = {inputStu, stuScoreAverage, stuCourseAverage, highestScore, meanVariance};
initialStu(&stu, S);
function(stu, S, C, fun);
freeStu(&stu);
system("pause");
return 0;
}
解答评论1
#include
#include
float average1(float a[][5], int n);
float average2(float a[][5], int b);
int main(){
int i,j;
float a[10][5];
for(i = 0; i
int c;
float k;
float sum = 0;
for(c = 0; c |