# include & ltstdio.h & gt
typedef？ struct？ _ratim？ //Here, specifically distinguish yourself from my previous answer. If you don't, you must use the struct keyword before using it.
{
int？ Molecule;
int？ Denominator;
} ratim
int？ gcd(int？ x，int？ Y)// Euclid uses division to find the greatest common divisor of two numbers.
{
if(x & lt； y)
Return? gcd(y，x)；
if(x%y！ =0)
Return? gcd(y，x % y)；
Or what? Return? y；
}
int？ count(int？ a，int？ b，int？ S)// Calculate addition, subtraction, multiplication and division
{
int？ Plus sign, minus sign, time; //Addition, subtraction and multiplication
plus = a+b；
Printf ("The sum of two rational numbers is: %d\\%d\n", plus, s); //Add
Minus = a-b;
Printf ("Find the reduction of two rational number pairs: %d\\%d\n", minus, s); //minus sign
Time = a * b；;
Printf ("Multiply two rational numbers: %d\\%d", time, s); //Multiply
Printf ("The division of two rational numbers is: %d\\%d\n", a, b); //division
Return? 0; //You must return a value.
}
int？ Master ()
{
ratim？ k 1；
ratim？ k2；
int？ Lcm// Least common multiple
Printf ("Please enter the numerator and denominator of the first rational number: \ n");
do
{
CIN & gt； & gtk 1. Molecule & gt& gtk 1. Denominator;
If(k 1. denominator ==0)
Printf ("The data is illegal, please re-enter!" );
} while(k 1 . denominator = = 0)；
Printf ("Please enter the numerator and denominator of the second rational number: \ n");
do
{
CIN & gt； & gtk2. Molecule & gt& gtk2. Denominator;
If(k2. Denominator ==0)
Printf ("The data is illegal, please re-enter!" );
} while(k2 . denominator = = 0)；
Lcm=(k 1. molecule *k2. molecule) /gcd(k 1. molecule, k2. molecule); //Least common multiple
K 1. Denominator =lcm/k 1. Molecule *k 1. Denominator;
K2. Denominator =lcm/k2. Molecule *k2. Denominator;
K 1. Molecule = lcm
K2. Molecule = lcm
Printf ("These two rational numbers are:% d/%d,% d \% d \ n", K 1. numerator, K 1. denominator, K2. numerator, K2. denominator);
Count(k 1. numerator, k2. numerator, k 1. denominator);
Printf ("The greatest common divisor of two rational numbers is:% d \ \% d \ n", GCD (K 1. numerator, K2. numerator), K 1. denominator);
Return? 0; //You must return a value.
}