/** Author : ~swim~ Date : 31-May-2018 Description : [ASSIGNMENT] : Lambda expressions TASK : Write the following methods that return a lambda expression performing a specified action : 1. PerformOperation isOdd() : The lambda expression must return true if a number is odd or false if it is even. 2. PerformOperation isPrime() : The lambda expression must return true if a number is prime or false if it is composite. 3. PerformOperation isPalindrome() : The lambda expression must return true if a number is a palindrome or false if it is not. Sample Input : * The first line contains an integer, N (the number of test cases). * The N subsequent lines each describe a test case in the form of 2 space-separated integers : - The first integer specifies the condition to check for (1 for Odd/Even, 2 for Prime, or 3 for Palindrome). - The second integer denotes the number to be checked. 5 1 4 2 5 3 898 1 3 2 12 Sample Output : EVEN PRIME PALINDROME ODD COMPOSITE HappyCodings!:) Note: Comprehensive input checking is not done. */ #include #include #include #include using namespace std; using bignum = unsigned long long; using func=function; using Opmap = map; using Pair = pair; using Testdata = vector; auto isOdd = [](bignum num) { return (num & 1) ? "ODD" : "EVEN"; }; auto isPrime = [](bignum num) { if(num < 2) return "COMPOSITE"; if(2 == num) return "PRIME"; for(bignum i=2; i*i<=num; ++i) if(!(num % i)) return "COMPOSITE"; return "PRIME"; }; auto isPalindrome(bignum num) { bignum tmp{num}, palin{0}; for(;tmp;palin=palin*10 + tmp%10, tmp /= 10); return (palin == num) ? "PALINDROME" : "NOT PALINDROME"; }; auto Evaluate = [](Opmap& fmap, auto const& Td) { for(auto const& p:Td) { try { string res = fmap[p.first](p.second); cout << p.second << " ==> " << res << endl; } catch(bad_function_call) { cout << "No function available" " for choice " << p.first << endl; } } // end for }; int main() { // map of functions identiied by // integers Opmap fmap { {1, isOdd}, {2, isPrime}, {3, isPalindrome} }; int ntc; // no of test cases cin >> ntc; if(ntc < 0){ cout << "error, enter positive" " number\n"; return -1; } // read test cases as pair of // function id and data Testdata td; for(int i=0; i> fid; cin >> data; td.emplace_back(fid,data); } cout << endl; cout <<"Results for user data\n\n"; // process the data now Evaluate(fmap, td); cout << endl; cout << "Results for preconfigured" " test data\n\n"; // pre confugured test data Testdata pctd{ {1, 100}, //odd/even {2, 31}, //prime/composite {3, 1221}, //palindrome check {2, 56}, //prime/composite {1, 11}, //odd/even {3, 356} //palindrome check }; Evaluate(fmap, pctd); return 0; }

[Assignment] Lambda Expression.cpp