题解 | #整数与IP地址间的转换#

#include <iostream>
#include <sstream>
#include <string>
#include <vector>
using namespace std;
int pow_function(int a, int n) {
    int x = 1;
    for (int i = 0; i < n; i++) {
        x *= a;
    }
    return x;
}
int main() {
    string input1, input2;
    while (cin >> input1 >> input2) {
        istringstream s(input1);
        vector<int> v;
        string temp;
        while (getline(s, temp, '.')) {
            int a = stoi(temp);
            v.push_back(a);
        }
        long output = 0;
        for (int i = 0; i < v.size(); i++) {
            int x = pow_function(2, 24 - 8 * i);
            output += v[i] * x;
        }
        cout << output << endl;
        long n = stol(input2);
        vector<string> vs;
        int x = pow_function(2, 8);
        for (int i = 0; i < 4; i++) {
            vs.push_back(to_string(n % x));
            n /= x;
        }
        for (int i = vs.size() - 1; i >= 0; i--) {
            cout << vs[i];
            if (i != 0) {
                cout << '.';
            }
        }
    }
}
// 64 位输出请用 printf("%lld")