chore(C): Added pascals triangle code

algorithms/C/maths/pascals-triangle.c

@@ -0,0 +1,21 @@
+
+#include<stdio.h> 
+long factorial(int);  
+int main()  
+{  
+    int i, n, c;  
+    printf("Enter the number of rows you wish to see in pascal triangle\n");  
+    scanf("%d", & n);  
+    for (i = 0; i < n; i++) {  
+        for (c = 0; c <= (n - i - 2); c++) printf(" ");  
+        for (c = 0; c <= i; c++) printf("%ld ", factorial(i) / (factorial(c) * factorial(i - c)));  
+        printf("\n");  
+    }  
+    return 0;  
+}  
+long factorial(int n) {  
+    int c;  
+    long result = 1;  
+    for (c = 1; c <= n; c++) result = result * c;  
+    return result;  
+}