题解 | 密码验证合格程序

#include <iostream>
#include <string>
#include <vector>
#include <unordered_map>
#include <cctype>
using namespace std;

bool no_same_substr(const string& str) {
    unordered_map<string, int> last_substr_pos; //记录的int是最后一次子串的起始位置
    for(int i = 0; i < str.size() - 2; ++i) {
        string substr = str.substr(i, 3);
        if(last_substr_pos.find(substr) != last_substr_pos.end()) {
            if(i > last_substr_pos[substr] + 2) {
                return false;
            }
        } else {
            last_substr_pos[substr] = i;
        }
    }
    return true;
}

bool has_at_least_three_type(const string& str) {
    int has_digit = 0, has_upper = 0, has_lower = 0, has_special = 0;
    for(const char& c: str) {
        if(isdigit(c)) has_digit = 1;
        else if(isupper(c)) has_upper = 1;
        else if(islower(c)) has_lower = 1;
        else has_special = 1;
        if(has_special + has_digit + has_lower + has_upper >= 3) {
            return true;
        } //在里面可以提前返回 
    } 
    return false;
}

int main() {
    string str;
    vector<string> ans;
    while(cin >> str) {
        if(str.size() < 8) {
            ans.push_back("NG");
            continue;
        }
        if(!has_at_least_three_type(str)) {
            ans.push_back("NG");
            continue;
        }
        if(no_same_substr(str)) {
            ans.push_back("OK");
        } else ans.push_back("NG");
    }
    for(const string& s: ans) {
        cout << s << endl;
    }
    
    return 0;
}