实验7

任务4：

include <stdio.h>

include <stdlib.h>

int is_word(char x);
int main() {
FILE* fp;
char ch;
int i, line = 1, count = 0;

fp = fopen("D:/homework/data4.txt", "r");
if (!fp)
{
    printf("fail to open file to read\n");
    return 0;
}

while ((ch = fgetc(fp)) != EOF)
{

    if (is_word(ch))
    {
        count++;
    }
    if (ch == '\n')
    {
        line++;
    }
}
fclose(fp);
printf("data4.txt统计结果:\n");
printf("行数: %20d\n", line);
printf("字符数(不计空白符): %7d\n", count);

return 0;

}
int is_word(char x)
{
if (x != '\n' && x != ' ' && x != '\t')
return 1;
else
return 0;
}

任务5：

include <stdio.h>

include <string.h>

define N 10

typedef struct {
long id;
char name[20];
float objective;
float subjective;
float sum;
char result[10];
} STU;
void read(STU st[], int n);
void write(STU st[], int n);
void output(STU st[], int n);
int process(STU st[], int n, STU st_pass[]);
int main() {
STU stu[N], stu_pass[N];
int cnt;
double pass_rate;
printf("从文件读入%d个考生信息...\n", N);
read(stu, N);
printf("\n对考生成绩进行统计...\n");
cnt = process(stu, N, stu_pass);
printf("\n通过考试的名单:\n");
output(stu, N);
write(stu, N);
pass_rate = 1.0 * cnt / N;
printf("\n本次等级考试通过率: %.2f%%\n", pass_rate * 100);
return 0;
}
void output(STU st[], int n) {
int i;
printf("准考证号\t姓名\t客观题得分\t操作题得分\t总分\t\t结果\n");
for (i = 0; i < n; i++)
printf("%ld\t\t%s\t%.2f\t\t%.2f\t\t%.2f\t\t%s\n", st[i].id, st[i].name, st[i].objective, st[i].subjective, st[i].sum, st[i].result);
}
void read(STU st[], int n) {
int i;
FILE* fin;

fin = fopen("D:/homework/examinee.txt", "r");
if (!fin) {
    printf("fail to open file\n");
    return;
}

while (!feof(fin)) {
    for (i = 0; i < n; i++)
        fscanf(fin, "%ld %s %f %f", &st[i].id, st[i].name, &st[i].objective, &st[i].subjective);
}

fclose(fin);

}
void write(STU s[], int n) {
int i;

FILE* fp;

fp = fopen("D:/homework/list_pass.txt", "w");
if (!fp) {
    printf("fail to open file\n");
    return;
}

fprintf(fp, "%-15s%-25s%-20s%-20s%-20s%-20s\n", "准考证号", "姓名", "客观题得分", "操作题得分", "总分", "结果");
for (i = 0; i < n; i++) {
    if (strcmp(s[i].result, "通过") == 0)
        fprintf(fp, "%-15ld%-25s%-20.2f%-20.2f%-20.2f%-20s\n", s[i].id, s[i].name, s[i].objective, s[i].subjective, s[i].sum, s[i].result);
}

fclose(fp);

}
int process(STU st[], int n, STU st_pass[]) {
int i, j;
for (i = 0, j = 0; i < n; i++) {
st[i].sum = st[i].objective + st[i].subjective;
if (st[i].sum >= 60) {
strcpy(st[i].result, "通过");
st_pass[j++] = st[i];
}
else {
strcpy(st[i].result, "未通过");
}
}

return j;

}

任务6：

include <stdio.h>

include <stdlib.h>

include <string.h>

include <time.h>

define N 80

define L 20

define C 30

typedef struct {
char id[15];
char n[L];
char c[C];
} S;

int main() {
S s[N];
int ns = 0;
char fn[100];
FILE* fp, * ofp;

fp = fopen("D:/homework/list.txt", "r");
if (fp == NULL) {
    printf("打开list.txt失败.\n");
    return 1;
}

while (fscanf(fp, "%s %s %[^\n]", s[ns].id, s[ns].n, s[ns].c) == 3) {
    ns++;
    if (ns >= N) break;
}
fclose(fp);

if (ns == 0)
{
    printf("未找到学生信息.\n");
    return 0;
}

int si[5] = { -1 };
srand(time(NULL));
int cnt = 0;
while (cnt < 5)
{
    int idx = rand() % ns;
    int ex = 0;
    for (int i = 0; i < cnt; i++)
    {
        if (si[i] == idx)
        {
            ex = 1;
            break;
        }
    }
    if (!ex)
    {
        si[cnt] = idx;
        cnt++;
    }

}


printf("-----随机抽点名单------\n");
for (int i = 0; i < 5; i++) {
    int idx = si[i];
    printf("%s %s %s\n", s[idx].id, s[idx].n, s[idx].c);
}

printf("-----保存到文件-------\n");
printf("输入文件名：");
scanf("%s", fn);

ofp = fopen(fn, "w");
if (ofp == NULL) {
    printf("打开输出文件失败.\n");
    return 1;
}

for (int i = 0; i < 5; i++) {
    int idx = si[i];
    fprintf(ofp, "%s %s %s\n", s[idx].id, s[idx].n, s[idx].c);
}
fclose(ofp);

printf("保存成功!\n");

return 0;

}