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HJ39判断两个IP是否属于同一子网(中)

news 2025/7/5 20:01:47

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文章目录

前言
一、背景
二、
- 2.1
- 2.2
总结

前言

接上文HJ39判断两个IP是否属于同一子网

查了下，atoi可以转换负数。

修改成下面的代码

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>bool isTargetSonNet(int array[], int len)
{int tempArray[32] = {0};int tempArrayIndex = 0;for(int i = 0; i < len; i++){int data = array[i];if(data > 255 || data < 0){return false;}int index = ((tempArrayIndex + 1) * 8);while(data){int dat = data % 2;tempArray[--index] = dat;data /= 2;}tempArrayIndex++;}int count = 0;for(int i = 0; i + 1 < 32; i++){int temp = tempArray[i] - tempArray[i + 1];if(temp != 0 && temp != 1){return false;}if(temp == 1){count++;}}if(count != 1){return false;}return true;
}int main() {int a, b;char sonNet[20] = {'\0'};char ip1[20] = {'\0'};char ip2[20] = {'\0'};int arraySonNet[4] = {0};int arrayIp1[4] = {0};int arrayIp2[4] = {0};while (scanf("%s", sonNet) != EOF) { // 注意 while 处理多个 case// 64 位输出请用 printf("%lld") to char output = 'f';char delimiters[2] = ".";char* p = strtok(sonNet, delimiters);int index = 0;while(p != NULL){//printf("%s\n", p);int data = atoi(p);// if(data > 255)// {//     output = '1';//     break;// }// else if(data != 255 && data != 0)// {//     output = '1';//     break;// }arraySonNet[index++] = data;p = strtok(NULL, delimiters);}if(!isTargetSonNet(arraySonNet, 4)){output = '1';}if(output != 'f'){printf("%c\n", output);break;}if(scanf("%s", ip1) != EOF){p = strtok(ip1, delimiters);int index = 0;while(p != NULL){//printf("%s\n", p);int data = atoi(p);if(data > 255 || data < 0){output = '1';break;}arrayIp1[index++] = data;p = strtok(NULL, delimiters);}}if(output != 'f'){printf("%c\n", output);break;}if(scanf("%s", ip2) != EOF){p = strtok(ip2, delimiters);int index = 0;while(p != NULL){//printf("%s\n", p);int data = atoi(p);if(data > 255 || data < 0){output = '1';break;}arrayIp2[index++] = data;p = strtok(NULL, delimiters);}}if(output != 'f'){printf("%c\n", output);break;}int count = 0;for(int i = 0; i < 4; i++){if( (ip1[i] & sonNet[i]) == (ip2[i] & sonNet[i]) ){++count;}}if(output == 'f'){if(count == 4){output = '0';}else {output = '2';}}printf("%c\n", output);}return 0;
}

验证一下demo示例

示例有错误

255.255.255.0
192.168.224.256
192.168.10.4
255.0.0.0
193.194.202.15
232.43.7.59
255.255.255.0
192.168.0.254
192.168.0.1

输出 1

修改成下面的代码也不行

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>bool isTargetSonNet(int array[], int len)
{int tempArray[32] = {0};int tempArrayIndex = 0;for(int i = 0; i < len; i++){int data = array[i];if(data > 255 || data < 0){return false;}int index = ((tempArrayIndex + 1) * 8);while(data){int dat = data % 2;tempArray[--index] = dat;data /= 2;}tempArrayIndex++;}int count = 0;for(int i = 0; i + 1 < 32; i++){int temp = tempArray[i] - tempArray[i + 1];if(temp != 0 && temp != 1){return false;}if(temp == 1){count++;}}if(count != 1){return false;}return true;
}int main() {int a, b;char sonNet[20] = {'\0'};char ip1[20] = {'\0'};char ip2[20] = {'\0'};int arraySonNet[4] = {0};int arrayIp1[4] = {0};int arrayIp2[4] = {0};while (scanf("%s", sonNet) != EOF) { // 注意 while 处理多个 case// 64 位输出请用 printf("%lld") to char output = 'f';char delimiters[2] = ".";char* p = strtok(sonNet, delimiters);int index = 0;while(p != NULL){//printf("%s\n", p);int data = atoi(p);// if(data > 255)// {//     output = '1';//     break;// }// else if(data != 255 && data != 0)// {//     output = '1';//     break;// }arraySonNet[index++] = data;p = strtok(NULL, delimiters);}if(!isTargetSonNet(arraySonNet, 4)){output = '1';}if(output != 'f'){printf("%c\n", output);break;}if(scanf("%s", ip1) != EOF){p = strtok(ip1, delimiters);int index = 0;while(p != NULL){//printf("%s\n", p);int data = atoi(p);if(data > 255 || data < 0){output = '1';break;}arrayIp1[index++] = data;p = strtok(NULL, delimiters);}}if(output != 'f'){printf("%c\n", output);continue;}if(scanf("%s", ip2) != EOF){p = strtok(ip2, delimiters);int index = 0;while(p != NULL){//printf("%s\n", p);int data = atoi(p);if(data > 255 || data < 0){output = '1';break;}arrayIp2[index++] = data;p = strtok(NULL, delimiters);}}if(output != 'f'){printf("%c\n", output);continue;}int count = 0;for(int i = 0; i < 4; i++){if( (ip1[i] & sonNet[i]) == (ip2[i] & sonNet[i]) ){++count;}}if(output == 'f'){if(count == 4){output = '0';}else {output = '2';}}printf("%c\n", output);}return 0;
}