IP段去重

来源：互联网发布：starbound知乎编辑：程序博客网时间：2024/05/19 06:46

原文

下面的代码是从网上拷贝的，经过了一番学习研究后觉得写的比较好，就挂上来，也留作以后工作所用

这段代码的思想也是先排序，然后去重的

#include <stdio.h>#include <stdlib.h>typedef struct node {    unsigned int start;    unsigned int end;} Node;void print_out(unsigned int start_pos, unsigned int end_pos){    printf("%u.%u.%u.%u ", start_pos >> 24,                          start_pos >> 16 & 0xFF,                          start_pos >> 8 & 0xFF,                          start_pos & 0xFF);    printf("%u.%u.%u.%u\n", end_pos >> 24,                          end_pos >> 16 & 0xFF,                          end_pos >> 8 & 0xFF,                          end_pos & 0xFF);    return;}static intcmpNodep(const void *p1, const void *p2){    if (((Node *)p1)->start > ((Node *)p2)->start)        return 1;    if (((Node *)p1)->start < ((Node *)p2)->start)        return -1;    return (((Node *)p1)->end - ((Node *)p2)->end);}int main(){    unsigned int start_pos, end_pos;    unsigned int i, tmp;    int start[4], end[4];    Node node_array[3000];    int node_array_size;    node_array_size = 0;    while (1)    {        if (scanf("%u.%u.%u.%u %u.%u.%u.%u", &start[0], &start[1], &start[2], &start[3],                                             &end[0], &end[1], &end[2], &end[3]) <= 0)            break;        start_pos = start[0]*256*256*256 + start[1]*256*256 + start[2]*256 + start[3];        end_pos = end[0]*256*256*256 + end[1]*256*256 + end[2]*256 + end[3];        node_array[node_array_size].start = start_pos;        node_array[node_array_size].end = end_pos;        node_array_size++;    }    qsort(node_array, node_array_size, sizeof(Node), cmpNodep);    start_pos = node_array[0].start;     end_pos = node_array[0].end;     for (i=1; i<node_array_size; i++)    {        // If next start before current end (+1 for merge),// update the new end if necessary        if (node_array[i].start <= end_pos + 1)         {            if (node_array[i].end > end_pos)                 end_pos = node_array[i].end;        }        else         {    // If next start after current end,     // print this section and start new one            print_out(start_pos, end_pos);            start_pos = node_array[i].start;             end_pos = node_array[i].end;        }    }    print_out(start_pos, end_pos);            return 0;}

输入：

1.1.1.1 2.2.2.2
3.3.3.3 4.4.4.4
1.1.1.1 2.2.2.9
3.3.3.8 4.4.4.9
sdf

结果：
1.1.1.1 2.2.2.9
3.3.3.3 4.4.4.9

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