第九天学习
课外知识
ai的简洁循环
c
const char *prompt[3] = {"请输入你的名字：", "请输入你的学号：", "请输入你的成绩："};
for (int i = 0; i < 3; ++i) {
printf("%s", prompt[i]);
scanf("%31s", massage[time1][i]); // %31s 防止写越界
}
c
#include <stdio.h>
int main(void) {
int n;
printf("请输入元素个数：");
if (scanf("%d", &n) != 1 || n <= 0 || n > 1000) {
fprintf(stderr, "非法个数！\n");
return 1;
}
int a[n]; // C99 可变长数组（VLA）
printf("请输入 %d 个整数：", n);
for (int i = 0; i < n; ++i) {
if (scanf("%d", &a[i]) != 1) {
fprintf(stderr, "输入错误！\n");
return 1;
}
}
/* 打印验证 */
for (int i = 0; i < n; ++i)
printf("%d ", a[i]);
puts("");
return 0;
}一句话总结：
给 %c/%[ ] 等不自动跳过空白的格式加前导空格 是最简单、最通用的"吃掉换行符"技巧。
c
scanf(" %c", &ch); // %c 前面有空格查询系统
#include <stdio.h>
#include <string.h>
#include <windows.h>
char name1[10][32];
char password1[10][32];
char name[] = {0};
char password[] = {0};
int num = 0;
char massage[10][3][32];
void menu()
{
printf("*********\n");
printf("***** 1.创建账户 \n");
printf(" 2.登录账户 \n");
printf(" 3.查询信息 \n");
printf(" 4.退出 \n");
printf(" \n");
}
void creat()
{
printf("正在创建账户，请稍等。 \n");
Sleep(1000);
while (1)
{
printf("请输入账号:");
scanf(" %s", name1[num]);
printf("%s", name1[num]);
printf("请输入密码：");
scanf(" %s", password1[num]);
printf("账号为：%s ,密码为：%s \n", name1[num], password1[num]);
num++;
break;
}
}
void getin()
{
int time1 = num;
int time2 = num;
int flag = 0;
while (1)
{
err:
printf("请输入账号：\n");
scanf(" %s", name);
// while (getchar() != '\n')
// {}
while (time1 + 1)
{
int true1 = strcmp(name, name1[time1]);
if (true1 == 0)
{
break;
}
time1--;
if (time1 == -1)
{
printf("账号错误请重新输入! \n");
goto err;
}
}
break;
}
while (1)
{
err1:
printf("请输入密码： \n");
scanf(" %s", password);
while (getchar() != '\n')
{
}
while (time2 + 1)
{
int true2 = strcmp(password, password1[time2]);
if (true2 == 0)
{
break;
}
time2--;
}
if (time2 == -1)
{
printf("密码错误请重新输入! \n");
goto err1;
}
break;
}
for (int i = 0; i < 3; i++)
{
if (i == 0)
{
printf("请输入你的名字：");
scanf(" %s", massage[time1][i]);
continue;
}
if (i == 1)
{
printf("请输入你的学号：");
scanf(" %s", massage[time1][i]);
continue;
}
if (i == 2)
{
printf("请输入你的成绩：");
scanf(" %s", massage[time1][i]);
continue;
}
}
printf("您查询的序号为:%d \n", time1);
}
void found()
{
printf("请输入你的查询序号：");
int a = 0;
scanf(" %d", &a);
for (int i = 0; i < 3; i++)
{
switch (i)
{
case 0:
printf("您的名字为：%s \n", massage[a][i]);
break;
case 1:
printf("您的学号为：%s \n", massage[a][i]);
break;
case 2:
printf("您的成绩为：%s \n", massage[a][i]);
break;
default:
break;
}
}
}
int main(int argc, char const *argv[])
{
menu();
int chose = 0;
printf("请输入你的选择：");
while (1)
{
scanf("%d", &chose);
if (chose == 1)
{
creat();
Sleep(1000);
menu();
continue;
}
if (chose == 2)
{
getin();
Sleep(1000);
menu();
continue;
}
if (chose == 3)
{
found();
Sleep(1000);
menu();
continue;
}
if (chose == 4)
{
printf("下次再见！");
break;
}
else
{
printf("选择错误，请重新输入:");
continue;
}
}
return 0;}