NPU machine test to determine whether the IP address legitimate

Topic Description

Determining whether the IP address valid, N rows, in the input string, ABCD format, are each an integer, the output is determined as a valid IP

输入样例：
2
1.2.3.4
172.168.0.300
输出：
Yes
No

Code

#include <iostream>
#include <string.h>
using namespace std;

int main()
{
    int n;
    cin>>n;
    while(n--) {
        char s[100];
        cin>>s;
        int flag=1;
        char *part=strtok(s,".");
        while(part) {
            int num=stoi(part);
            if(num<0||num>255) {
                cout<<"No"<<endl;
                flag=0;
                break;
            }
            else
                part=strtok(NULL,".");
        }
        if(flag)
            cout<<"Yes"<<endl;
    }
}

Additional knowledge

strtok

1. function prototype

char *strtok(char s[], const char *delim);

2. header file

string.h

3. Function Function

Resolving string is a set of strings. s is the string to be decomposed, the delim a delimiter character (if incoming string, each character string passed both delimiter). When the first call, s point to the string to break down, and again after the call should s set to NULL.

4. Return Value: returns a string pointer to the next after a split, if the split has been unable to return NULL

An array of pointers to strings and string

char *s="abc";A pointer pointing to a string constant, this time constant stored in the area abc, s stack pointer to the string can only access can not be modified, may be varied pointers

char s[10]="abc"; Stored in the stack area you can be modified

If you read only two can be used, modified only by an array of characters