"%lf",&score
时间: 2024-08-23 18:02:37 浏览: 31
`%lf`是一个用于C语言中的格式控制符,它表示浮点数(double类型的数值)。当你在输出或输入操作中使用这个格式符,如printf或scanf函数时,它会匹配相应的变量类型,这里是double类型,比如`score`。例如:
```c
double score;
printf("请输入分数:");
scanf("%lf", &score); // 使用&score获取score变量的地址,以便读取浮点数输入
```
在这个例子中,`&score`表示score变量的内存地址,`%lf`告诉scanf函数应该从那个地址读取一个双精度浮点数。
相关问题
检查以下代码 找出可能出错的地方#include<stdio.h> struct student{ int num; char name; double score1,score2,score3; double average; }; int main(void) { int i,j,k; int n; struct student stu[50],temp; scanf("%d",&n); for(i=0;i<n;i++){ scanf("%d",&stu[i].num); scanf("%s",&stu[i].name); scanf("%lf%lf%lf",&stu[i].score1,&stu[i].score2,&stu[i].score3); stu[i].average = (stu[i].score1+stu[i].score2+stu[i].score3)/3.0; } int index; for(i=0;i<n-1;i++){ index = i; for(j=i+1;j<n;j++){ if(stu[i].average>stu[index].average){ index = i; } } temp = stu[i]; stu[i] = stu[index]; stu[index] = temp; } for(i=0;i<n;i++){ printf("%d,%.2f\n",stu[i].num,stu[i].average); }
在代码中可能出错的地方是:
1. 在结构体中,name应该是一个字符串类型,而不是字符类型,应该定义为char name[20]或者char *name。
2. 在第21行的if语句中,应该比较stu[j].average和stu[index].average,而不是stu[i].average和stu[index].average。
正确的代码如下:
```c
#include<stdio.h>
struct student{
int num;
char name[20]; // name应该是一个字符串类型
double score1,score2,score3;
double average;
};
int main(void) {
int i,j,k;
int n;
struct student stu[50],temp;
scanf("%d",&n);
for(i=0;i<n;i++){
scanf("%d",&stu[i].num);
scanf("%s",stu[i].name);
scanf("%lf%lf%lf",&stu[i].score1,&stu[i].score2,&stu[i].score3);
stu[i].average = (stu[i].score1+stu[i].score2+stu[i].score3)/3.0;
}
int index;
for(i=0;i<n-1;i++){
index = i;
for(j=i+1;j<n;j++){ // 比较stu[j].average和stu[index].average
if(stu[j].average>stu[index].average){
index = j;
}
}
temp = stu[i];
stu[i] = stu[index];
stu[index] = temp;
}
for(i=0;i<n;i++){
printf("%d,%.2f\n",stu[i].num,stu[i].average);
}
return 0;
}
```
#include <stdio.h> #include <stdlib.h> #include <string.h> typedef struct { char name[20]; double averageScore; double moralityScore; double finalScore; } Student; int cmp(const void* a, const void* b) { Student* studentA = (Student*)a; Student* studentB = (Student*)b; return studentB->finalScore - studentA->finalScore; } int main() { FILE* inFile = fopen("rawscore.txt", "r"); if (!inFile) { fprintf(stderr, "无法打开文件\n"); return 1; } int studentCount, subjectCount; fscanf(inFile, "%d %d", &studentCount, &subjectCount); Student* students = (Student*)malloc(studentCount * sizeof(Student)); for (int i = 0; i < studentCount; i++) { fscanf(inFile, "%s", students[i].name); double sum = 0; for (int j = 0; j < subjectCount; j++) { double score; fscanf(inFile, "%lf", &score); sum += score; } students[i].averageScore = sum / subjectCount; fscanf(inFile, "%lf", &students[i].moralityScore); } double academicWeight, moralityWeight; printf("请输入专业课成绩与德育成绩之间的比例(如0.7):"); scanf("%lf", &academicWeight); moralityWeight = 1 - academicWeight; for (int i = 0; i < studentCount; i++) { students[i].finalScore = students[i].averageScore * academicWeight + students[i].moralityScore * moralityWeight; } qsort(students, studentCount, sizeof(Student), cmp); int scholarshipLevelCount; printf("请输入奖学金等级数:"); scanf("%d", &scholarshipLevelCount); for (int i = 1; i <= scholarshipLevelCount; i++) { int count; printf("请输入%d等奖的获奖人数:", i); scanf("%d", &count); printf("%d等奖获得者:\n", i); for (int j = 0; j < count; j++) { printf("%s %.2lf\n", students[j].name, students[j].finalScore); } memmove(students, students + count, (studentCount - count) * sizeof(Student)); studentCount -= count; } free(students); return 0; }
这段代码是用来计算学生的最终成绩并根据成绩给出奖学金等级的。程序首先读取一个文本文件,该文件包含了每个学生的姓名、各门课程的成绩以及德育成绩。然后程序通过输入专业课成绩与德育成绩之间的比例来计算每个学生的最终成绩,最终成绩由专业课成绩和德育成绩加权得出。程序使用快速排序算法对学生按照最终成绩进行排序,然后根据输入的奖学金等级数依次给出各个等级的获奖人数和获奖名单。最后释放动态分配的内存并退出程序。