遍历查找
思路：从数组头循环遍历至数组尾，对比查找，知道对比成功，然后输出。
代码实现：
#include<stdio.h>
#pragma warning(disable:4996)
int main()
{
int a[] = {
0,1,3,4,6,7,9,19,32,37 };
int num = sizeof(a) / sizeof(a[0]);
int n = 0;
scanf("%d", &n);
int i = 0;
for (; i < num; i++) {
if (a[i] == n) {
printf("ture\n");
break;
}
}
if (i >= num) {
printf("false\n");
}
system("pause");
return 0;
}二分查找
思路：二分査找就是折半查找，其基本思想是：首先选取表中间位置的记录为关键字，将其关键字与给定关键字 n 进行比较，若相等，则査找成功；若 n 值比该关键字值大，则要找的元素一定在右子表中，则继续对右子表进行折半查找：若 n 值比该关键字值小，则要找的元素一定在左子表中，继续对左子表进行折半査找。如此递推，直到査找成功或査找失败（或査找范围为 0）。
画图解析：
代码实现：
#include<stdio.h>
#include<windows.h>
#pragma warning(disable:4996)
int Search(int a[], int n, int y)
{
int L = 0;
int R = n - 1;
while (L < R) {
int mid = (L + R) / 2;
if (y > a[mid]) {
L = mid + 1;
}
else if (y < a[mid]) {
R = mid - 1;
}
else {
return 1;
}
}
return 0;
}
int main()
{
int a[] = {
0,1,3,4,6,7,9,19,32,37 };
int num = sizeof(a) / sizeof(a[0]);
int b = 0;
int result = 0;
printf("Please Enter your number:\n");
while(1){
scanf("%d", &b);
result = Search(a, num, b);
if (result){
printf("Yes!you get!");
break;
}
else{
printf("No!you don't get!Please try again:\n");
}
}
system("pause");
return 0;
}猜数字游戏
有了上面查找算法的基础，我们来做一个简单的小时候经常的小游戏吧！
为了提升小游戏的真实实用性，加入了登录程序界面。
#include<stdio.h>
#include<windows.h>
#include<time.h>
#pragma warning(disable:4996)
const char *name = "xuenuo";
const char *key = "104934";
void Showtime();
void Login();
void Game();
void Play();
void Login()//登录
{
int chance = 3;
int time = 1;
while (chance > 0) {
char N[50];
char K[50];
printf("Please Enter your name:\n");
scanf("%s", &N);
printf("Please Enter your key:\n");
scanf("%s", &K);
if (0 == strcmp(name, N) && 0 == strcmp(key, K)) {
Showtime();
break;
}
else {
printf("Your Enter Message Is Error!\n");
chance--;
printf("You have %d more chances\n", chance);
}
if (chance <= 0) {
printf("You have no chance,Lock %d s,Wait....\n", time * 10);
Sleep(10000 * time);
chance = 3;
time++;
if (time >= 3) {
printf("You never get a chance!\n");
break;
}
}
}
}
void Showtime()//登录成功展示
{
char word_str[] = "Login success!";
char sym_str[] = "##############";
int left = 0;
int right = strlen(word_str) - 1;
printf("%s\n", sym_str);
while (left <= right) {
sym_str[left] = word_str[left];
sym_str[right] = word_str[right];
printf("%s\r", sym_str);
left++, right--;
Sleep(500);
}
printf("\n");
}
void Game()
{
while (1) {
int select = 0;
printf("###################################\n");
printf("######### 1. Play 2. Exit #######\n");
printf("###################################\n");
printf("Please Select: ");
scanf("%d", &select);
switch (select)
{
case 1:
Play();
break;
case 2:
printf("See you again!\n");
return;
default:
printf("Enter Error! Try Again\n");
break;
}
}
}
void Play()
{
srand((unsigned long)time(NULL));
int x = rand() % 200 + 1;//[1..200]
int data;
while (1) {
printf("Guess: ");
scanf("%d", &data);
if (data > x) {
printf("guess Big!\n");
}
else if (data < x) {
printf("guess Small!\n");
}
else {
printf("guess Right!\n");
break;
}
}
}
int main()
{
Login();
Game();
system("pause");
return 0;
}