add radix sort

README.md

@@ -1,13 +1,13 @@
 ## WIP WIP WIP
 
 # TODO
-- [] Algorithms to be implemented:
+- [ ] Algorithms to be implemented:
     - [x] Bubblesort
     - [x] SelectionSort
     - [x] InsertionSort
-    - [] Radix Sort
+    - [x] Radix Sort
 - [x] Implement Score system
-- [] Code Refactoring/Cleaning
+- [ ] Code Refactoring/Cleaning
 
 ## Levels:
 1: 5 elems\

src/main.c

@@ -8,7 +8,7 @@
 const int EASY_SCORE_DECREMENT = 10;
 const int MEDIUM_SCORE_DECREMENT = 20;
 const int LOWER = 1;
-const int UPPER = 3;
+const int UPPER = 4;
 
 typedef enum Difficulty {
   Easy,
@@ -56,7 +56,9 @@ int main(int argc, char *argv[]) {
       getarr(size);
       selectionsort(list, size);
       break;
-    // case 4: radixsort(list); break;
+    case 4:
+      radixsort(list, size);
+      break;
     default:
       break;
     }

src/sort.c

@@ -39,3 +39,41 @@ void insertionsort(int a[], int n) {
     printf("\n");
   }
 }
+
+int get_max(int a[], int n) {
+  int max = a[0];
+  int i;
+  for (i = 1; i < n; i++)
+    if (a[i] > max)
+      max = a[i];
+  return max;
+}
+void radixsort(int a[], int n) {
+  int bucket[10][10], bucket_cnt[10];
+  int i, j, k, r, NOP = 0, divisor = 1, lar, pass;
+  lar = get_max(a, n);
+  while (lar > 0) {
+    NOP++;
+    lar /= 10;
+  }
+  for (pass = 0; pass < NOP; pass++) {
+    for (i = 0; i < 10; i++) {
+      bucket_cnt[i] = 0;
+    }
+    for (i = 0; i < n; i++) {
+      r = (a[i] / divisor) % 10;
+      bucket[r][bucket_cnt[r]] = a[i];
+      bucket_cnt[r] += 1;
+    }
+    i = 0;
+    for (k = 0; k < 10; k++) {
+      for (j = 0; j < bucket_cnt[k]; j++) {
+        a[i] = bucket[k][j];
+        i++;
+      }
+    }
+    divisor *= 10;
+    printarr(a, n);
+    printf("\n");
+  }
+}

src/sort.h

@@ -4,4 +4,4 @@
 void bubblesort(int a[], int n);
 void selectionsort(int a[], int n);
 void insertionsort(int a[], int n);
-void radixsort(int a[]);
+void radixsort(int a[], int n);