Initial data commit

Task/Forward-difference/C/forward-difference-2.c

@@ -0,0 +1,33 @@
+#include <stdio.h>
+
+int* binomCoeff(int n) {
+     int *b = calloc(n+1,sizeof(int));
+     int j;
+     b[0] = n%2 ? -1 : 1;
+     for (j=1 ; j<=n; j++)
+           b[j] = -b[j-1]*(n+1-j)/j;
+
+     return(b);
+};
+
+main () {
+    double array[] = { 90, 47, 58, 29, 22, 32, 55, 5, 55, 73 };
+    size_t lenArray = sizeof(array)/sizeof(array[0]);	
+
+    int p = 4;  // order
+    int *b = binomCoeff(p);   // pre-compute binomial coefficients for order p
+
+    int j, k;
+
+    // compute p-th difference
+    for (k=0 ; k < lenArray; k++)
+        for (array[k] *= b[0], j=1 ; j<=p; j++)
+            array[k] += b[j] * array[k+j];
+
+    free(b);
+
+    // resulting series is shorter by p elements
+    lenArray -= p; 	
+    for (k=0 ; k < lenArray; k++)  printf("%f ",array[k]);
+    printf("\n");
+}