题解 | #在字符串中找出连续最长的数字串#

#include <bits/stdc++.h>
using namespace std;

int main() {
    string s;
    while (cin >> s) { // 注意 while 处理多个 case
        size_t pos = 0;
        int count = 1;
        int maxlen = 0;
        vector<string> res;
        for(int i = 0; i < s.size(); ++i){
            if(isdigit(s[i])){
                pos = i;
                break;
            }
        }
        int i = pos + 1;
        for(; i < s.size(); ++i){
            if(isdigit(s[i]) && isdigit(s[i - 1])){
                ++count;
            }
            else if(!isdigit(s[i]) && isdigit(s[i - 1])){
                if(count > maxlen){
                    maxlen = count;
                    
                    res.clear();
                    res.emplace_back(s.substr(pos, i - pos));
                }
                else if(count == maxlen){
                    res.emplace_back(s.substr(pos, i - pos));
                }
                //查找下一个数字起始位置
                pos = s.find_first_of("0123456789", i);
                if(pos == std::string::npos){
                    count = 0;  //后面没有数字了
                    break;
                }
                i = pos;  //i应该变为 pos + 1，加一的工作交给 ++i去做了，否则会错误 
                count = 1;
            }
        }
        if(count > maxlen){
            res.clear();
            res.emplace_back(s.substr(pos, i - pos));
        }
        else if(count == maxlen){
            res.emplace_back(s.substr(pos, i - pos));
        }
        for(string &str : res){
            cout << str;
        }
        cout << "," << res[0].length() << endl;
    }
}
// 64 位输出请用 printf("%lld")