P58459 - Dates vàlides

#include<iostream>
using namespace std;

bool es_data_valida (int x, int y, int z) {
    bool traspas;

    if ((z%100 == 0 and (z/100)%4 == 0) or (z%4 == 0 and z%100 != 0)) traspas = true;
    else traspas = false;

    if (x > 31 or y > 12 or x < 1 or y <1) return false;
    else if (y == 2 and (x > 29 or (x == 29 and not traspas))) return false;
    else if (x == 31 and (y == 2 or y == 4 or y == 6 or y == 9 or y == 11)) return false;
    else return true;
}