test_1_24
#define _CRT_SECURE_NO_WARNINGS 1#include <stdio.h>int main()
{int arr[5] = {1,2,3,4,5};//完全初始化int arr2[100] = { 1,2,3,4,5 };//不完全初始化 - 剩余没有初始化的默认给的是0int arr3[4] = { 1,2,3,4};return 0;
}int main()
{int a = 10;int arr[10];//int 是数组元素的类型//数组arr 的类型是int [10]//return 0;
}int main()
{int arr1[5];//int [5]int arr2[6];//int [6]return 0;
}int main()
{int arr[10] = { 1,2,3,4,5,6,7,8,9,10 };printf("%d\n", arr[5]);//[] -- 下标引用操作符int i = 0;for (i = 0; i < 10; i++){printf("%d ", arr[i]);}printf("%d\n", arr[10]);//errreturn 0;
}int main()
{int arr[10] = { 0 };//int i = 0;//输入for (i = 0; i < 10; i++){scanf("%d", &arr[i]);}//输出数组的内容for (i = 0; i < 10; i++){printf("%d ", arr[i]);}return 0;
}int main()
{int arr[10] = { 0 };//int i = 0;//输入scanf("%d %d %d %d %d %d %d %d %d %d", &arr[0], &arr[1], &arr[2], &arr[3], &arr[4], &arr[5], &arr[6], &arr[7], &arr[8], &arr[9]);//输出数组的内容for (i = 0; i < 10; i++){printf("%d ", arr[i]);}return 0;
}int main()
{int arr1[10] = { 0 };int arr2[10] = { 1,2,3,4,5 };int arr3[] = { 1,2,3,4,5,6,7,8,9,10 };int arr4[] = { 0 };//这个数组几个元素？return 0;
}%p 是专门用来打印地址的
特点：16进制的形式打印，同时最前面的0不会省略
%x 是16进制的形式打印int main()
{int arr[10] = { 0 };int i = 0;for (i = 0; i < 10; i++){printf("&arr[%d] = %#X\n", i, &arr[i]);}return 0;
}
strlen - 求字符串长度的，只能针对字符串int main()
{int arr[10] = { 1,2,3,4,5 };printf("%zd\n", sizeof(arr));//sizeof(数组名) - 计算的是整个数组的单位是字节printf("%zd\n", sizeof(int [10]));printf("%zd\n", sizeof(arr[0]));//计算的是一个元素占据空间的大小，单位是字节printf("%d\n", sizeof(arr) / sizeof(arr[0]));return 0;
}int main()
{int arr[] = { 1,2,3,4,5,6,7,8,9,10 ,9,8,7,6,5,4,3,2,1};int sz = sizeof(arr) / sizeof(arr[0]);int i = 0;for (i = 0; i < sz; i++){printf("%d ", arr[i]);}return 0;
}int main()
{int arr1[3][5] = {1,2,3,4,5, 2,3,4,5,6, 3,4,5,6,7};//完全初始化int arr2[3][5] = { 1,2 };//完全初始化，剩余的元素默认初始化为0int arr3[3][5] = { 1,2,3,4,5,6,7 };int arr4[3][5] = { {1,2},{3,4,5 }, { 6,7 }};int arr[3][5] = { (1,2),(3,4)};//errreturn 0;
}int main()
{int arr[][5] = { 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17 };int arr[3][5] = { 1,2,3,4,5, 2,3,4,5,6, 3,4,5,6,7 };printf("%d\n", arr[1][2]);printf("%d\n", arr[0][0]);//printf("%d\n", arr[3][5]);//errreturn 0;
}int main()
{int arr[3][5] = { 0 };//输入int i = 0;for (i = 2; i >=0; i--){int j = 0;for (j = 0; j < 5; j++){scanf("%d", &arr[i][j]);}}//输出for (i = 0; i < 3; i++){int j = 0;for (j = 0; j < 5; j++){printf("%d ", arr[i][j]);}printf("\n");}return 0;
}int main()
{int arr[3][5] = { 0 };int i = 0;for (i = 0; i < 3; i++){int j = 0;for (j = 0; j < 5; j++){printf("&arr[%d][%d] = %p\n", i, j, &arr[i][j]);}}return 0;
}int main()
{int arr1[10];int arr2[3+5];int arr3[] = {1,2,3,4};int score[40];return 0;
}int main()
{int n = 0;scanf("%d", &n);//30int arr[n];//return 0;
}#include <windows.h>
#include <string.h>
#include <stdlib.h>int main()
{char arr1[] = "welcome to bit!!!!!";char arr2[] = "###################";int left = 0;int right = strlen(arr1)-1;while (left<=right){arr2[left] = arr1[left];arr2[right] = arr1[right];printf("%s\n", arr2);Sleep(1000);//单位是毫秒system("cls");left++;right--;}printf("%s\n", arr2);return 0;
}题目：
在一个有序的数组中查找指定的数，是否存在，存在则打印下标，不存在则说明不存在！int main()
{int arr[] = { 1,2,3,4,5,6,7,8,9,10 };int k = 0;scanf("%d", &k);//7int sz = sizeof(arr) / sizeof(arr[0]);int i = 0;for (i = 0; i < sz; i++){if (arr[i] == k){printf("找到了，下标是:%d\n", i);break;}}if (i == sz)printf("找不到了\n");return 0;
}int main()
{int arr[] = { 1,2,3,4,5,6,7,8,9,10 };int k = 0;scanf("%d", &k);在arr数组中找kint sz = sizeof(arr) / sizeof(arr[0]);//10int left = 0;int right = sz - 1;while (left<=right){int mid = (left + right) / 2;if (arr[mid] < k)left = mid + 1;else if (arr[mid] > k)right = mid - 1;else{printf("找到了,下标是：%d\n", mid);break;}}if (left > right)printf("找不到了\n");return 0;
}
