4-6-1 删除字符(函数题)

接口：

void delchar( char *str, char c );

其中char *str是传入的字符串，c是待删除的字符。函数delchar的功能是将字符串str中出现的所有c字符删除。

void delchar(char* str, char c) 
{char* p = str;char* q = str;while (*p) {if (*p != c) {*q = *p;q++;}p++;}*q = '\0';
}

4-6-2 数组循环右移(函数题)

接口：

void ArrayShift( int a[], int n, int m );

其中a[ ]是用户传入的数组；n是数组的大小；m是右移的位数。函数ArrayShift须将循环右移后的数组仍然存在a[]中

void ArrayShift( int a[], int n, int m )
{int x = m % n; //减少循环次数for(int i = 0;i<x;i++){int tmp = a[n-1];for(int j = n-1;j>0;j--){a[j] = a[j-1];}a[0] = tmp;}
}

4-6-3 使用函数实现字符串部分复制(函数题)

接口：

void strmcpy( char *t, int m, char *s );

函数strmcpy将输入字符串char *t中从第m个字符开始的全部字符复制到字符串char *s中。若m超过输入字符串的长度，则结果字符串应为空串。

void strmcpy(char *t, int m, char *s) 
{int len = strlen(t);if (m > len) {*s = '\0';return;}strcpy(s, t + m - 1);//有库函数就直接调用
}

4-7-1 校验ISBN-10编码

#include<stdio.h>
int main()
{int n = 0, flag = 1;scanf("%d",&n);char cr[11] = { '0' };for (int i = 0; i < n; i++){scanf("%s",cr);int sum = 0;int j = 0;for ( j = 0; j < 10; j++){if(cr[j]!='X')sum += (j + 1) * (cr[j] - '0');elsesum+=(j+1)*10;}if (sum % 11 != 0){flag=0;printf("%s\n",cr);}}if (flag == 1){printf("All passed");}return 0;
}

4-7-2 删除重复字符

#include<stdio.h>
#include<string.h>
int Judg(char* ret,int j,char check)
{int i = 0;for(i = 0;i<j;i++){if(*(ret+i) == check)return 0;}return 1;}
void Bubble_sort(char* a,int len)
{int i,j,tmp;for(i = 0;i<len-1;i++){for(j = 0;j<len-1-i;j++){if(a[j]>a[j+1]){tmp = a[j];a[j] = a[j+1];a[j+1] = tmp;}}}
}
int main()
{char arr[90] = {0};char ret[90] = {0};gets(arr);//int len = strlen(arr);int i = 0,j = 0;while(arr[i]!='\0'){if(Judg(ret,j,arr[i])){ret[j]=arr[i];j++;i++;}elsei++;}ret[j]='\0';Bubble_sort(ret,j);printf("%s",ret);return 0;
}

4-7-3 字符串转换成十进制整数

#include<stdio.h>
#include<string.h>
#include<math.h>
int main()
{char arr[1000] = { 0 };scanf("%s", arr);int len = strlen(arr);int i = 0;char ret[990] = { 0 };int j = 0;for (i = 0; i < len - 1; i++){if ((arr[i] >= 48 && arr[i] <= 57) || (arr[i] >= 65 && arr[i] <= 70) || (arr[i] >= 97 && arr[i] <= 102)){ret[j] = arr[i];j++;}}int f = 1;int len2 = 0;for (i = 0; i < len - 1; i++){if (ret[0] == arr[i]){len2 = i;break;}}for (int k = len2 - 1; k >= 0; k--){if (arr[k] == '-'){f = -1;break;}}int re = 0;for (int m = 0; m < j; m++){if (ret[m] >= '0' && ret[m] <= '9'){re += (ret[m] - '0') * pow(16, j - 1 - m);}else if ((ret[m] >= 'a' && ret[m] <= 'f')){re += (ret[m] - 'a' + 10) * pow(16, j - 1 - m);}else if (ret[m] >= 'A' && ret[m] <= 'F'){re += (ret[m] - 'A' + 10) * pow(16, j - 1 - m);}}re *= f;printf("%d", re);return 0;
}

4-7-4 IP地址转换

#include<stdio.h>
#include<math.h>
int main()
{char bin[35] = {0};scanf("%s",bin);int a=0;for(int i = 0;i<8;i++){a += (bin[i]-'0')*pow(2,7-i);}printf("%d.",a);a = 0;for(int i = 8;i<16;i++){a += (bin[i]-'0')*pow(2,15-i);}printf("%d.",a);a = 0;for(int i = 16;i<24;i++){a += (bin[i]-'0')*pow(2,23-i);}printf("%d.",a);a = 0;for(int i = 24;i<32;i++){a += (bin[i]-'0')*pow(2,31-i);}printf("%d",a);return 0;
}