1
#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
int menu() {
printf("********************\n");
printf("**** 1:开始游戏 ****\n");
printf("**** 0:结束游戏 ****\n");
printf("********************\n");
return 0;
}
int game() {
int randomnum = rand() % 10 + 1;
int input = 0;
while (1) {
printf("请输入您猜的数字：");
scanf("%d", &input);
if (input > randomnum) {
printf("猜大了\n");
}
else if (input < randomnum) {
printf("猜小了\n");
}
else {
printf("恭喜您猜对了!!!\n");
}
}
}
int main() {
int input = 0;
srand((unsigned)time(NULL));
do {
menu();
printf("请选择:");
scanf("%d", &input);
switch (input) {
case 1:
game();
break;
case 0:
break;
default:
printf("您的选择有误，请重新输入：\n");
break;
}
} while (input);
return 0;
}
2
#include <stdio.h>
#include <stdlib.h>
int main(){
int arr[] = { 1,2,3,4,5,6,7,8,9 };
int tofind = 2;
int left = 0;
int right = sizeof(arr) / sizeof(arr[0]) - 1;
while (left <= right) {
int mid = (left + right) / 2;
if (arr[mid] < tofind) {
left = mid + 1;
}
else if (arr[mid] > tofind) {
right = mid - 1;
}
else {
printf("找到了，下标是:%d\n",mid);
break;
}
if (left > right) {
printf("没找到\n");
}
}
system("pause");
return 0;
}
3
#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
int main(){
int i = 0;
for (; i < 3; i++) {
char password[1024] = { 0 };
printf("请输入您的密码:\n");
scanf("%s", &password);
if (strcmp(password, "374272") == 0) {
printf("登陆成功\n");
break;
}
else {
printf("您的密码有误，请重试\n");
}
}
if (i == 3) {
printf("您已经输错三次\n");
}
system("pause");
return 0;
}
4
#include <stdio.h>
#include <stdlib.h>
int main(){
int t = 0;
printf("请输入一个字符：");
t = getchar();
if (t >= 'a' && t <= 'z'){
putchar(t - 32);
}
else if (t >= 'A' && t <= 'Z') {
putchar(t + 32);
}
else if (t >= '0' && t <= '9'){
;
}
printf("\n");
system("pause");
return 0;
}
