/* This program generates and checks 10 digit numbers * where each digit is unique and the number is a * multiple of 10. * * Demonstrates the use of: * std::to_string() * std::stoll() * std::is_permutation() * * No user input required. */ #include #include #include #include #include using namespace std; // Declare functions long long createnumber(); bool isvalid(long long n); void showvalidity(long long x); // Program entry point int main(){ // declare variable long long x; // seed random number generator srand(time(NULL)); cout << "==== Expected Valid ====" << endl; // create and validate numbers for(int i=0; i<10; i++){ x = createnumber(); showvalidity(x); } cout << "==== Expected Invalid ====" << endl; // create and validate bad numbers // not modulo 10 for(int i=1; i<10; i++){ x = createnumber(); x += i; showvalidity(x); } // create and validate bad permutations x = 2058467390; // multiple 0's showvalidity(x); x = 2158467310; // multiple 1's showvalidity(x); x = 2158467320; // multiple 2's showvalidity(x); x = 2358467390; // multiple 3's showvalidity(x); x = 2458467390; // multiple 4's showvalidity(x); x = 2558467390; // multiple 5's showvalidity(x); x = 2658467390; // multiple 6's showvalidity(x); x = 2758467390; // multiple 7's showvalidity(x); x = 2858467390; // multiple 8's showvalidity(x); x = 2958467390; // multiple 9's showvalidity(x); // create and validate out of range numbers x = 1000; showvalidity(x); x = 9876543220; showvalidity(x); return 0; } /* Function to validate 10 digit number. The number * must contain 10 unique digits aand be a multiple * of 10. * * Input: long long integer * * Output: True if number is valid otherwise false * */ bool isvalid(long long n){ // declare variables string a = "1234567890"; string b; // is it below the minimum possible value? if(n < 1234567890){ return false; } // is it above the maximum possible value? if(n > 9876543210){ return false; } // is it evenly divisible by 10? if( n%10 != 0){ return false; } // create a string equivalent to the number b = to_string(n); // check the string is a valid permutation if(is_permutation(a.begin(), a.end(), b.begin())){ return true; } else { return false; } } /* Function to generate a 10 digit number having * unique digits and is a multiple of 10. * * Inputs: None * * Outputs: long long integer as specified * */ long long createnumber(){ string str = "1234567890"; random_shuffle(str.begin(), str.end()-1); return stoll(str); } /* Convenience funtion to display a long long integer * and validity status. * * Inputs: long long integer to display and validate * * Outputs: Displays integer and ststus on screen, * returns nothing. * */ void showvalidity(long long x){ cout << x; if(isvalid(x)){ cout << " is valid" << endl; } else { cout << " is invalid" << endl; } } /* * The author of this work hereby waives all claim of copyright (economic * and moral) in this work and immediately places it in the public domain; * it may be used, distorted or destroyed in any manner whatsoever without * further attribution or notice to the creator. */

10 Digit Number Permutations