C++中提取字符串中的连续数字

以下是C++中提取字符串中的连续数字的方法：

方法一：使用isdigit()函数和stringstream类

#include <iostream>
#include <string>
#include <sstream>

using namespace std;

void extractNumbers(string str, int* arr, int& count) {
    stringstream ss(str);
    string temp;
    while (ss >> temp) {
        int num = 0;
        for (int i = 0; i < temp.length(); i++) {
            if (isdigit(temp[i])) {
                num = num * 10 + (temp[i] - '0');
            }
            else {
                if (num != 0) {
                    arr[count++] = num;
                    num = 0;
                }
            }
        }
        if (num != 0) {
            arr[count++] = num;
        }
    }
}

int main() {
    string str = "abc2345 345fdf678 jdhfg945";
    int arr[100];
    int count = 0;
    extractNumbers(str, arr, count);
    for (int i = 0; i < count; i++) {
        cout << arr[i] << " ";
    }
    cout << endl;
    cout << "共有" << count << "个整数" << endl;
    return 0;
}

方法二：使用正则表达式

#include <iostream>
#include <string>
#include <regex>

using namespace std;

void extractNumbers(string str, int* arr, int& count) {
    regex reg("\\d+");
    smatch result;
    while (regex_search(str, result, reg)) {
        arr[count++] = stoi(result[0]);
        str = result.suffix().str();
    }
}

int main() {
    string str = "abc2345 345fdf678 jdhfg945";
    int arr[100];
    int count = 0;
    extractNumbers(str, arr, count);
    for (int i = 0; i < count; i++) {
        cout << arr[i] << " ";
    }
    cout << endl;
    cout << "共有" << count << "个整数" << endl;
    return 0;
}