System

学生成绩管理系统代码

#include <stdio.h> #include <stdlib.h> #include <string.h> #define MAX_LEN 10 // 字符串最大长度 #define STU_NUM 30 // 最多的学生人数 #define COURSE_NUM 6 // 最多的考试科目数 typedef struct student { long num; // 每个学生的学号 char name[MAX_LEN]; // 每个学生的姓名 float score[COURSE_NUM]; // 每个学生COURSE_NUM门功课的成绩 float sum; // 每个学生的总成绩 float aver; // 每个学生的平均成绩 }STU; int Menu(void); void ReadScore(STU stu[], int n, int m); void AverSumofEveryStudent(STU stu[], int n, int m); void AverSumofEveryCourse(STU stu[], int n, int m); void SortbyScore(STU stu[],int n,int m,int (*compare)(float a,float b)); int Ascending(float a, float b); int Descending(float a, float b); void SwapFloat(float *x, float *y); void SwapLong(long *x, long *y); void SwapChar(char x[], char y[]); void AsSortbyNum(STU stu[], int n, int m); void SortbyName(STU stu[], int n, int m); void SearchbyNum(STU stu[], int n, int m); void SearchbyName(STU stu[], int n, int m); void StatisticAnalysis(STU stu[], int n, int m); void PrintScore(STU stu[], int n, int m); void WritetoFile(STU record[], int n, int m); void ReadfromFile(STU record[], int *n, int m); int main(void) { char ch; int n = 0, m = 0; STU stu[STU_NUM]; printf("Input student number(n<%d):", STU_NUM); scanf("%d", &n); printf("Input course number(m<=%d):",COURSE_NUM); scanf("%d", &m); while (1) { ch = Menu(); // 显示菜单，并读取用户输入 switch (ch) { case 1:ReadScore(stu, n, m); break; case 2: AverSumofEveryCourse(stu, n, m);
break; case 3: AverSumofEveryStudent(stu, n, m);
break; case 4: SortbyScore(stu, n, m, Descending); printf("\nSort in descending order by score:\n"); PrintScore(stu, n, m); break; case 5: SortbyScore(stu, n, m, Ascending); printf("\nSort in ascending order by score:\n"); PrintScore(stu, n, m); break; case 6: AsSortbyNum(stu, n, m); printf("\nSort in ascending order by number:\n"); PrintScore(stu, n, m); break; case 7: SortbyName(stu, n, m); printf("\nSort in dictionary order by name:\n"); PrintScore(stu, n, m); break; case 8: SearchbyNum(stu, n, m); break; case 9: SearchbyName(stu, n, m); break; case 10: StatisticAnalysis(stu, n, m); break; case 11:PrintScore(stu, n, m); break; case 12:WritetoFile(stu, n, m); break; case 13:ReadfromFile(stu, &n, &m); break; case 0: printf("End of program!"); exit(0); default:printf("Input error!"); } } return 0;} // 函数功能：显示菜单并获得用户键盘输入的选项 int Menu(void) { int itemSelected; printf("Management for Students' scores\n"); printf("1.Input record\n"); printf("2.Calculate total and average score of every course\n"); printf("3.Calculate total and average score of every student\n"); printf("4.Sort in descending order by score\n"); printf("5.Sort in ascending order by score\n"); printf("6.Sort in ascending order by number\n"); printf("7.Sort in dictionary order by name\n"); printf("8.Search by number\n"); printf("9.Search by name\n"); printf("10.Statistic analysis\n"); printf("11.List record\n"); printf("12.Write to a file\n"); printf("13.Read from a file\n"); printf("0.Exit\n"); printf("Please Input your choice:"); scanf("%d", &itemSelected); // 读入用户输入 return itemSelected; } // 函数功能：输入n个学生的m门课成绩 void ReadScore(STU stu[], int n, int m) { int i, j; printf("Input student's ID, name and score:\n"); / ---------- begain ---------- */ for(i=0;i<n;i++) {scanf("%ld%s",&stu[i].num,stu[i].name); for (j=0; j<m; j++) scanf("%f",&stu[i].score[j]); }

/* ----------- end ----------- */

} // 函数功能：计算每个学生各门课程的总分和平均分 void AverSumofEveryStudent(STU stu[], int n, int m) { int i, j; for (i=0; i<n; i++) { stu[i].sum = 0; for (j=0; j<m; j++) { stu[i].sum = stu[i].sum + stu[i].score[j]; } stu[i].aver = m>0 ? stu[i].sum / m : -1; printf("student %d: sum = %.0f, aver = %.0f\n", i+1, stu[i].sum, stu[i].aver); } } // 函数功能：计算每门课程的总分和平均分 void AverSumofEveryCourse(STU stu[], int n, int m) { int i, j; float sum[COURSE_NUM], aver[COURSE_NUM]; /* ---------- begain ---------- / for (j=0; j<m; j++) { sum[j] = 0; for (i=0; i<n; i++) { sum[j] += stu[i].score[j]; } aver[j]=sum[j]/i; printf("student %d: sum = %.0f, aver = %.0f\n", j+1, sum[j], aver[j]); } / ----------- end ----------- */ } // 函数功能：按选择法将数组sum的元素值排序 void SortbyScore(STU stu[],int n,int m,int (*compare)(float a,float b)) { int i, j, k, t; for (i=0; i<n-1; i++) { k = i; for (j=i+1; j<n; j++) { if ((*compare)(stu[j].sum, stu[k].sum)) k = j; } if (k != i) {
for (t=0; t<m; t++) // 交换m门课程的成绩 { SwapFloat(&stu[k].score[t], &stu[i].score[t]); } SwapFloat(&stu[k].sum, &stu[i].sum); // 交换总分 SwapFloat(&stu[k].aver, &stu[i].aver); // 交换平均分
SwapLong(&stu[k].num, &stu[i].num); // 交换学号 SwapChar(stu[k].name, stu[i].name); // 交换姓名 } } } // 使数据按升序排序 int Ascending(float a, float b) { return a < b; // 这样比较决定了按升序排序，如果a<b，则交换 } // 使数据按降序排序 int Descending(float a, float b) { return a > b; // 这样比较决定了按降序排序，如果a>b，则交换 } // 交换两个单精度浮点型数据 void SwapFloat(float *x, float *y) { float temp; temp = *x; *x = *y;
*y = temp; } // 交换两个长整型数据 void SwapLong(long *x, long *y) { long temp; temp = *x; *x = *y;
y = temp; } // 交换两个字符串 void SwapChar(char x[], char y[]) { char temp[MAX_LEN]; strcpy(temp, x); strcpy(x, y); strcpy(y, temp); } // 函数功能：按选择法将数组num的元素值按从低到高排序 void AsSortbyNum(STU stu[], int n, int m) { int i, j, k, t; for (i=0; i<n-1; i++) { / ---------- begain ---------- */

    /* ----------- end ----------- */
}

} // 函数功能：交换法实现字符串按字典顺序排序 void SortbyName(STU stu[], int n, int m) { int i, j, t; for (i=0; i<n-1; i++) { for (j = i+1; j<n; j++) { if (strcmp(stu[j].name, stu[i].name) < 0) {
for (t=0; t<m; t++)// 交换m门课程的成绩 { SwapFloat(&stu[i].score[t], &stu[j].score[t]); } SwapFloat(&stu[i].sum, &stu[j].sum); // 交换总分 SwapFloat(&stu[i].aver, &stu[j].aver); // 交换平均分
SwapLong(&stu[i].num, &stu[j].num); // 交换学号 SwapChar(stu[i].name, stu[j].name); // 交换姓名 } } } } // 函数功能：按学号查找学生成绩并显示查找结果 void SearchbyNum(STU stu[], int n, int m) { long number; int i, j; printf("Input the number you want to search:"); scanf("%ld", &number);

/* ---------- begain ---------- */

/* ----------- end ----------- */

printf("\nNot found!\n");

} // 函数功能：按姓名的字典顺序排出成绩表 void SearchbyName(STU stu[], int n, int m) { char x[MAX_LEN]; int i, j; printf("Input the name you want to search:"); scanf("%s", x); for (i=0; i<n; i++) { if (strcmp(stu[i].name, x) == 0) { printf("%ld\t%s\t", stu[i].num, stu[i].name); for (j=0; j<m; j++) { printf("%.0f\t", stu[i].score[j]); } printf("%.0f\t%.0f\n", stu[i].sum, stu[i].aver); return; } } printf("\nNot found!\n"); } // 函数功能：统计各分数段的学生人数及所占的百分比 void StatisticAnalysis(STU stu[], int n, int m) { int i, j, t[6]; for (j=0; j<m; j++) { printf("For course %d:\n", j+1); memset(t, 0, sizeof(t)); // 将数组t的全部元素初始化为0 for (i=0; i<n; i++) { if (stu[i].score[j]>=0 && stu[i].score[j]<60)t[0]++; else if (stu[i].score[j]<70) t[1]++; else if (stu[i].score[j]<80) t[2]++; else if (stu[i].score[j]<90) t[3]++; else if (stu[i].score[j]<100) t[4]++; else if (stu[i].score[j] == 100) t[5]++; } for (i=0; i<=5; i++) { if (i==0) printf("<60\t%d\t%.2f%%\n",t[i],(float)t[i]/n*100); else if (i==5) printf("%d\t%d\t%.2f%%\n", (i+5)10,t[i],(float)t[i]/n100); else printf("%d-%d\t%d\t%.2f%%\n", (i+5)*10, (i+5)10+9, t[i], (float)t[i]/n100); } } } // 函数功能： 打印学生成绩 void PrintScore(STU stu[], int n, int m) { int i, j; for (i=0; i<n; i++) { printf("%ld\t%s\t", stu[i].num, stu[i].name); for (j=0; j<m; j++) { printf("%.0f\t", stu[i].score[j]); } printf("%.0f\t%.0f\n", stu[i].sum, stu[i].aver); } } // 输出n个学生的学号、姓名及m门课程的成绩到文件student.txt中 void WritetoFile(STU stu[], int n, int m) { FILE *fp; int i, j;

if ((fp = fopen("student.txt","w")) == NULL) 
{ 
	printf("Failure to open score.txt!\n");
	exit(0);
}

fprintf(fp, "%d\t%d\n", n, m); //将学生人数和课程门数写入文件 for (i=0; i<n; i++) { fprintf(fp, "%10ld%10s", stu[i].num, stu[i].name); for (j=0; j<m; j++) { fprintf(fp, "%10.0f", stu[i].score[j]); } fprintf(fp, "%10.0f%10.0f\n", stu[i].sum, stu[i].aver); } fclose(fp); } //从文件中读取学生的学号、姓名及成绩等信息写入到结构体数组stu中 void ReadfromFile(STU stu[],int *n, int *m) { FILE *fp; int i, j; if ((fp = fopen("student.txt","r")) == NULL) { printf("Failure to open score.txt!\n"); exit(0); } fscanf(fp, "%d\t%d", n, m); // 从文件中读出学生人数和课程门数
for (i=0; i<*n; i++) //学生人数保存在n指向的存储单元 { fscanf(fp, "%10ld", &stu[i].num); fscanf(fp, "%10s", stu[i].name);
for (j=0; j<*m; j++)//课程门数保存在m指向的存储单元 { fscanf(fp, "%10f", &stu[i].score[j]); //不能用%10.0f } fscanf(fp, "%10f%10f", &stu[i].sum, &stu[i].aver);//不能用%10.0f } fclose(fp); }