A calculator for big numbers - c

Question

i have to code a calculator that does adding or multiplication to numbers with maximum digits of 30 .(maximum number of operands i can enter is 20).
and this is what i came up with (it is long):
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
void Adding(int Result[31],int temp[30][31],int cnt)
{
int remainder,i,j,ResultsA[60]={0};
for(i=0;i<30;i++)
{
for(j=0;j<30;j++)
{
ResultsA[j]=(ResultsA[j]+temp[i][j])%10;
remainder=(ResultsA[j]+temp[i][j])/10;
ResultsA[j+1] += remainder;
if(ResultsA[30])
{
cnt++;
}
}
}
for(i=0;i<30;i++)
{
Result[i]=ResultsA[i];
}
for(i=0;i<30;i++)
{
for(j=0;j<30;j++)
{
temp[i][j]=0;
}
}
return;
}
void Mul(int num,int Results[31],int Num_int[30][31],int cnt)
{
int remainder=0,i,j,rows,x;
for(i=0;i<1;i++)
{
Results[i]=1;
}
int temp[30][31]={0};
for(rows=0;rows<num;rows++)
{
for(i=0;i<30;i++)
{
for(j=0;j<30;j++)
{
temp[i][i+j]=remainder+(Num_int[rows][j]*Results[i])%10;
remainder=(Num_int[rows][j]*Results[i])/10;
}
}
Adding(Results,temp,cnt);
}
return;
}
void Plus(int num,int Nums_int[30][31],int Results[31],int cnt)
{
int i,j,remainder,len=0;
for(i=0;i<num;i++)
{
for(j=0;j<30;j++)
{
Results[j]=(Results[j]+Nums_int[i][j])%10;
remainder=(Results[j]+Nums_int[i][j])/10;
Results[j+1]+=remainder;
if(Results[30])
cnt++;
}
}
return;
}
void str_to_int(int Nums_int[20][31],char Nums_str[20][31])
{
int length[20]={0},i,j;
for(i=0;i<20;i++)
{
for(j=19;0<=j;j--)
{
while(Nums_str[i][j]<48||57<Nums_str[i][j])
length[i]++;
}
}
for(i=0;i<20;i++)
{
for(j=0;j<length[i];j++)
{
Nums_int[i][length[i]-j]=Nums_str[i][j]-'0';
}
}
return;
}
void calcBig(char op, int operands[][31], int numOperands, int result[31],int cnt)
{
if (op=='+')
{
Plus(numOperands,operands,result,cnt);
}
if(op=='*')
{
Mul(numOperands,result,operands,cnt);
}
return;
}
int main()
{
int i,cnt=0,y;
char x;
char Nums_str[20][31]={0};
int num, Nums_int[30][31]={0};
int Results[31]={0};
printf("select operator:\n");
scanf("%c",&x);
printf("enter number of operands:\n");
scanf("%d",&num);
printf("enter numbers <seperated by new line>:\n");
for(i=0;i<num;i++)
{
scanf("%s",Nums_str[i]);
}
str_to_int(Nums_int,Nums_str);
calcBig(x,Nums_int,num,Results,cnt);
printf("result:\n");
if(cnt)
{
printf("overflow!");
}
else{
for(i=29;0<=i;i--)
{
while(Results==0)
{
y++;
}
}
for(i=y;0<=i;i--)
{
printf("%d",&Results[i]);
}
}
return 0;
}
Num_int is the 2d array containing numbers from user , num is the number of numbers entered by user.
Mul is function for multiplying numbers in Nums_int.
str_to_int converts the number recieved from user from string to int and reverse the order.
Plus is a function to add numbers in Nums_int.
Adding is function to add numbers that are the result of multiplying a number by ever digit of the other numbers (it gives the result of multiplying two numbers).
the problem is that when i run the code i get this:
select the operation:
*/+
select number of operands:
num
enter numbers:
//entering numbers
and after entering the numbers nothing happens and the program doesnt even end (no return 0). simply nothing happens after entering the numbers