题目1475：IP数据包解析

来源：互联网发布：电脑防蓝光软件编辑：程序博客网时间：2024/06/06 02:06
#include<stdio.h>  #include<string.h>  int num(char *c) {               // 字符转换为数字       if (*c >= '0'&&*c <= '9') return *c - '0';    else return *c - 'a' + 10;}int sum1(char *p) {    // 求地址       return 16 * num(p) + num(p + 1);}int sum2(char *p) {             // 求端口       return 256 * 16 * num(p) + 256 * num(p + 1) + 16 * num(p + 3) + num(p + 4);}int main() {    int n, c = 1;     while (scanf("%d", &n) != EOF)          {        char str[1000];        gets(str);        while (n--)         {             gets(str);                    //从缓冲区获取字符串                int IHL = num(str + 1) * 4 * 3;      //计算ip头部长度.                printf("Case #%d\nTotal length = %d bytes\n", c++, sum2(str + 6));            printf("Source = %d.%d.%d.%d\n", sum1(str + 36), sum1(str + 39), sum1(str + 42), sum1(str + 45));            printf("Destination = %d.%d.%d.%d\n", sum1(str + 48), sum1(str + 51), sum1(str + 54), sum1(str + 57));            printf("Source Port = %d\n", sum2(str + IHL));            printf("Destination Port = %d\n\n", sum2(str + IHL + 6));        }    }    return 0;}/**************************************************************    Problem: 1475    User: cust123    Language: C++    Result: Accepted    Time:0 ms    Memory:1020 kb****************************************************************/
0 1