diff --git a/README.md b/README.md
index 4571d6d..1958668 100644
--- a/README.md
+++ b/README.md
@@ -71,9 +71,12 @@ _WDP\* MIM UW_
   - [next_perm](./src/cw3/zad12/next_perm.c): autor: @lbozyk (C) :white_check_mark:
 - [zad. 14.] sprawdź, czy jeden ciąg zawiera się w drugim
   - [subsequence](./src/cw3/zad14/subsequence.c) (C) :white_check_mark::microscope:
-- [zad. 16.] ciąg róznicowy
+- [zad. 16.] ciąg różnicowy
   - [differential_sequence](./src/cw3/zad16/differential_sequence.c) (C)
   - [diff_seq](./src/cw3/zad16/diff_seq.c) (C): autor: @lbozyk (C) :white_check_mark:
+  - [diff_seq_fam](./src/cw3/zad16/diff_seq_fam.c) (C) :white_check_mark::microscope:
+- [zad. 17.] ciąg ciągu różnicowego
+  - [diff_diff_seq_fam](./src/cw3/zad17/diff_diff_seq_fam.c) (C) :white_check_mark::microscope:
 
 ### Laboratorium II: [Gra w skakanie (NWD)](./pdf/WDP_.Inf.23_24Z__Zadanie_rozgrzewkowe_2.pdf) 2023.10.11
 
@@ -130,6 +133,8 @@ _WDP\* MIM UW_
 - [zad. 15.]
   - [zad_15](./src/cw5/zad15/zad_ms.c): autor: @MrD4rkne (C) :white_check_mark::microscope:
   - [zad15](./src/cw5/zad15/zad15.c): autor: @pixelkubek (C) :white_check_mark:
+- [zad. 17.]
+  - [orzechy](./src/cw5/zad17/orzechy.c) (C) :white_check_mark::microscope:
 - [zad. 18.]
   - [zad18](./src/cw5/Zad18/zad18.c): autor: @pixelkubek (C) :white_check_mark:
 
diff --git a/src/cw3/zad16/diff_seq_fam.c b/src/cw3/zad16/diff_seq_fam.c
new file mode 100644
index 0000000..075721e
--- /dev/null
+++ b/src/cw3/zad16/diff_seq_fam.c
@@ -0,0 +1,42 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+//Uses https://en.wikipedia.org/wiki/Flexible_array_member at end of struct
+typedef struct {
+  int dl;
+  double el[];
+} ciag;
+
+ciag *roznicowy(ciag *c) {
+  ciag *r = malloc(sizeof(ciag) + (size_t)(c->dl - 1) * sizeof(double));
+  r->dl = c->dl - 1;
+
+  for (int i = 0; i < r->dl; i++)
+    r->el[i] = c->el[i + 1] - c->el[i];
+
+  return r;
+}
+
+ciag *readCiag() {
+  int dl;
+  if(!scanf("%d", &dl)) printf("wrong input");
+
+  ciag *c = malloc(sizeof(ciag) + (size_t)dl * sizeof(double));
+  c->dl = dl;
+
+  for (int i = 0; i < dl; i++)
+    if(!scanf("%lf", &(c->el[i]))) printf("wrong input");
+
+  return c;
+}
+
+void printCiag(ciag *c) {
+  for (int i = 0; i < c->dl; i++)
+    printf("%lf ", c->el[i]);
+}
+
+int main() {
+  ciag *c = readCiag();
+
+  printCiag(roznicowy(c));
+}
\ No newline at end of file
diff --git a/src/cw3/zad17/diff_diff_seq_fam.c b/src/cw3/zad17/diff_diff_seq_fam.c
new file mode 100644
index 0000000..cf8a895
--- /dev/null
+++ b/src/cw3/zad17/diff_diff_seq_fam.c
@@ -0,0 +1,51 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+//Uses https://en.wikipedia.org/wiki/Flexible_array_member at end of struct
+typedef struct ciag {
+  int dl;
+  struct ciag *next;
+  double el[];
+} ciag;
+
+ciag *roznicowyRec(ciag *c) {
+  c->next = malloc(sizeof(ciag) + (size_t)(c->dl - 1) * sizeof(double));
+  c->next->dl = c->dl - 1;
+  c->next->next = NULL;
+
+  for (int i = 0; i < c->next->dl; i++)
+    c->next->el[i] = c->el[i + 1] - c->el[i];
+
+  if(c->next->dl != 0) roznicowyRec(c->next);
+
+  return c;
+}
+
+ciag *readCiag() {
+  int dl;
+  if(!scanf("%d", &dl)) printf("wrong input");
+
+  ciag *c = malloc(sizeof(ciag) + (size_t)dl * sizeof(double));
+  c->dl = dl;
+  c->next = NULL;
+
+  for (int i = 0; i < dl; i++)
+    if(!scanf("%lf", &(c->el[i]))) printf("wrong input");
+
+  return c;
+}
+
+void printCiag(ciag *c) {
+  for (int i = 0; i < c->dl; i++)
+    printf("%lf ", c->el[i]);
+
+  printf("\n");
+
+  if(c->next != NULL) printCiag(c->next);
+}
+
+int main() {
+  ciag *c = readCiag();
+
+  printCiag(roznicowyRec(c));
+}
\ No newline at end of file
diff --git a/src/cw5/zad17/orzechy.c b/src/cw5/zad17/orzechy.c
new file mode 100644
index 0000000..dde48b2
--- /dev/null
+++ b/src/cw5/zad17/orzechy.c
@@ -0,0 +1,59 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#define x_size 6
+#define y_size 4
+
+int orzechy(int a[x_size][y_size], int k) {
+  int sumPref[x_size + 1][y_size + 1];
+
+  //Obliczanie sumy prefiksowej
+  for (int y = 0; y < y_size + 1; y++) {
+    for (int x = 0; x < x_size + 1; x++) {
+      if (x == 0 || y == 0) {
+        sumPref[x][y] = 0;
+      } else {
+        sumPref[x][y] = a[x - 1][y - 1] + sumPref[x - 1][y] +
+                        sumPref[x][y - 1] - sumPref[x - 1][y - 1];
+      }
+    }
+  }
+
+  int maks = 0;
+
+  //Sprawdzanie wszystkich prostokątów zaczynających się w x i y
+  for (int x = 0; x < x_size; x++) {
+    for (int y = 0; y < y_size; y++) {
+      for (int w = 1; w <= k && x + w <= x_size; w++) {
+        if (k % w != 0)
+          continue;
+
+        int h = k / w;
+
+        if (y + h > y_size)
+          continue;
+
+        int suma = sumPref[x + w][y + h] - sumPref[x][y + h] -
+                   sumPref[x + w][y] + sumPref[x][y];
+
+        if (suma > maks)
+          maks = suma;
+      }
+    }
+  }
+
+  return maks;
+}
+
+int main() {
+  int k;
+  int t[x_size][y_size];
+
+  for (int y = 0; y < y_size; y++)
+    for (int x = 0; x < x_size; x++)
+      if(!scanf("%d", &t[x][y])) printf("wrong input");
+
+  if(!scanf("%d", &k)) printf("wrong input");
+
+  printf("%d", orzechy(t, k));
+}
\ No newline at end of file
diff --git a/src/kol1_22/zad1/schodki.c b/src/kol1_22/zad1/schodki.c
index db8f9da..a3d3978 100644
--- a/src/kol1_22/zad1/schodki.c
+++ b/src/kol1_22/zad1/schodki.c
@@ -5,7 +5,7 @@
 // M(n)
 
 int schodki(int n, int t[]) {
-  int *pom = (int*)malloc((size_t)(n+1)*sizeof(int));
+  int *pom = (int*)calloc((size_t)(n+1), sizeof(int));
   int ile = 0; 
 
   for(int i=0; i<n; i++) {
diff --git a/tests/cw3/zad16/c/diff_seq_fam0.in b/tests/cw3/zad16/c/diff_seq_fam0.in
new file mode 100644
index 0000000..19a4084
--- /dev/null
+++ b/tests/cw3/zad16/c/diff_seq_fam0.in
@@ -0,0 +1 @@
+5 1 1 1 1 1
\ No newline at end of file
diff --git a/tests/cw3/zad16/c/diff_seq_fam0.out b/tests/cw3/zad16/c/diff_seq_fam0.out
new file mode 100644
index 0000000..ce979c4
--- /dev/null
+++ b/tests/cw3/zad16/c/diff_seq_fam0.out
@@ -0,0 +1 @@
+0.000000 0.000000 0.000000 0.000000
\ No newline at end of file
diff --git a/tests/cw3/zad16/c/diff_seq_fam1.in b/tests/cw3/zad16/c/diff_seq_fam1.in
new file mode 100644
index 0000000..a0959b7
--- /dev/null
+++ b/tests/cw3/zad16/c/diff_seq_fam1.in
@@ -0,0 +1 @@
+6 1 2 3 4 5 6
\ No newline at end of file
diff --git a/tests/cw3/zad16/c/diff_seq_fam1.out b/tests/cw3/zad16/c/diff_seq_fam1.out
new file mode 100644
index 0000000..621e646
--- /dev/null
+++ b/tests/cw3/zad16/c/diff_seq_fam1.out
@@ -0,0 +1 @@
+1.000000 1.000000 1.000000 1.000000 1.000000
\ No newline at end of file
diff --git a/tests/cw3/zad16/c/diff_seq_fam2.in b/tests/cw3/zad16/c/diff_seq_fam2.in
new file mode 100644
index 0000000..7d2e72a
--- /dev/null
+++ b/tests/cw3/zad16/c/diff_seq_fam2.in
@@ -0,0 +1 @@
+10 1 6 -3 2 10 12 3 5 24 0
\ No newline at end of file
diff --git a/tests/cw3/zad16/c/diff_seq_fam2.out b/tests/cw3/zad16/c/diff_seq_fam2.out
new file mode 100644
index 0000000..ee1215c
--- /dev/null
+++ b/tests/cw3/zad16/c/diff_seq_fam2.out
@@ -0,0 +1 @@
+5.000000 -9.000000 5.000000 8.000000 2.000000 -9.000000 2.000000 19.000000 -24.000000
\ No newline at end of file
diff --git a/tests/cw3/zad17/c/diff_diff_seq_fam0.in b/tests/cw3/zad17/c/diff_diff_seq_fam0.in
new file mode 100644
index 0000000..60388ca
--- /dev/null
+++ b/tests/cw3/zad17/c/diff_diff_seq_fam0.in
@@ -0,0 +1 @@
+4 1 2 4 7
\ No newline at end of file
diff --git a/tests/cw3/zad17/c/diff_diff_seq_fam0.out b/tests/cw3/zad17/c/diff_diff_seq_fam0.out
new file mode 100644
index 0000000..b03a07a
--- /dev/null
+++ b/tests/cw3/zad17/c/diff_diff_seq_fam0.out
@@ -0,0 +1,4 @@
+1.000000 2.000000 4.000000 7.000000 
+1.000000 2.000000 3.000000 
+1.000000 1.000000 
+0.000000
\ No newline at end of file
diff --git a/tests/cw5/zad17/c/orzechy0.in b/tests/cw5/zad17/c/orzechy0.in
new file mode 100644
index 0000000..1fdf1ba
--- /dev/null
+++ b/tests/cw5/zad17/c/orzechy0.in
@@ -0,0 +1,6 @@
+0 0 4 1 2 0
+3 3 8 11 3 2
+1 3 9 8 1 2
+2 1 1 2 0 12
+
+6
\ No newline at end of file
diff --git a/tests/cw5/zad17/c/orzechy0.out b/tests/cw5/zad17/c/orzechy0.out
new file mode 100644
index 0000000..f70d7bb
--- /dev/null
+++ b/tests/cw5/zad17/c/orzechy0.out
@@ -0,0 +1 @@
+42
\ No newline at end of file