#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <iostream>
//binomial coefficient (n k) = n!/(k!*(n-k)!)
double binom (int n, int k);
// product of n*(n-1)*…*k
double fact (int n, int k);
int main()
{
int i;
int j;
int n=10; // rows’ number by default
int lastStrLenght=0;
int spcNum=0;
printf(“Enter a number of rows: “); //10 rows by default
//scanf(“%d”, &n);
std::cin >> n;
printf(“%d\nPascal’s Triangle for %d rows\n”, n, n);
char prstr[100];
*prstr = ‘\0′;
//dynamic allocation memory for rows
double ** ptri;
ptri = (double**) malloc(n*sizeof(double));
for (i=0; i<n; i++) {
ptri[i] = (double*) malloc((i+1)*sizeof(double));
}
//calculating of binomial coefficients and adding it to dynamic array
for (i=0; i<n; i++) {
for(j=0; j<i+1; j++) {
ptri[i][j] = binom(i, j);
}
}
//calculating of max row lenght
for (j=0; j<n; j++) {
sprintf (prstr, “%.0f “, ptri[n-1][j]);
lastStrLenght += strlen(prstr);
}
char str[lastStrLenght];
*str=’\0′;
//printing of dynamic array
for (i=0; i<n; i++) {
for (j=0; j<i+1; j++) {
sprintf (prstr, “%.0f “, ptri[i][j]);
strcat (str, prstr);
}
//printing spaces to align current row about last row
spcNum = (lastStrLenght – strlen(str))/2;
for (j=1; j<=spcNum; j++) {
printf (” “);
} //
printf (“%s\n”, str); //printing of current row
*str=’\0’;
}
//free the array memory
for (i=0; i<n; i++){
free(ptri[i]);
}
free(ptri); //
return 0;
}
//binomial coefficient (n k) = n!/(k!*(n-k)!)
double binom (int n, int k)
{
double res = 1;
if (k>(n-k)) { // which bigger k or n-k
res = fact(n, k+1)/fact(n-k, 1); // n! / k!*(n-k)! = n*(n-1)*…*(k+1)/(n-k)*(n-k-1)*…*1
}
else {
res = fact(n, n-k+1)/fact(k, 1); // n! / k!*(n-k)! = n*(n-1)*…*(n-k+1)/k*(k-1)*…*1
}
return res;
}
// product of n*(n-1)*…*k
double fact (int n, int k)
{
int i;
double res = 1;
for (i=k; i<=n; i++) {
res*=i;
}
return res;
}