### 存储例题

#include <stdio.h>int main(){  unsigned char a = 200;  //原码00000000 00000000 00000000 11001000  //无符号char类型 只能在内存里存储 11001000  //运算时 无符号char类型整型提升 00000000 00000000 00000000 11001000  unsigned char b = 100;  //原码00000000 00000000 00000000 01100100  //无符号char类型 只能在内存里存储 01100100  //运算时 无符号char类型整型提升 00000000 00000000 00000000 01100100    unsigned char c = 0;    c = a + b;  //a+b 整型提升后进行运算  1 0010 1100  转换成原码之后 得到300  //只能在C中存储   0010 1100  整型提升后 得44  printf("%d %d", c,a+b);  return 0;}

### 杨辉三角

#define _CRT_SECURE_NO_WARNINGS 1#include <stdio.h>int main(){  int arr[10][10] = { 0 };  int i = 0;  int j = 0;  for (i = 0; i < 10; i++)  {    for (j = 0; j <= i; j++)    {      if (j == 0)      {        arr[i][j] = 1;      }      if (i == j)      {        arr[i][j] = 1;      }      if (i >= 2 && j >= 1)      {        arr[i][j] = arr[i - 1][j - 1] + arr[i - 1][j];       }          }      }  for (i = 0; i < 10; i++)  {    for (j = 0; j <= i; j++)    {      printf("%d ", arr[i][j]);    }    printf("\n");  }  return 0;}

### 找凶手

#define _CRT_SECURE_NO_WARNINGS 1#include <stdio.h>int main(){  char killer = 'A';  for (killer = 'A'; killer < 'D'; killer++)  {    if ((killer != 'A') + (killer == 'C') + (killer == "D") + (killer != 'D') == 3)    {      printf("%c\n",killer);    }  }  return 0;}