#include #include using namespace std; /* inputs a numeric grade and display messages according to its value 0 .. 30 fail 31 .. 50 low 51 .. 70 average 71 .. 100 good otherwise invalid grade */ int main() { int grade; string display; cout << "Please enter a grade between 0 and 100: "; cin >> grade; if (grade >= 0) { if (grade >= 51) { if (grade >= 71) { if (grade > 100) { display = "invalid grade"; } else { display = "good"; } } else { display = "average"; } } else { display = "low"; } } else { display = "invalid grade"; } cout << display << endl; return 0; }