1 files changed, 71 insertions, 0 deletions
diff --git a/semestr-5/so/lista1/so21_lista_1/het.c b/semestr-5/so/lista1/so21_lista_1/het.c
new file mode 100644
index 0000000..579abe4
--- /dev/null
+++ b/semestr-5/so/lista1/so21_lista_1/het.c
@@ -0,0 +1,71 @@
+#include "csapp.h"
+
+#define CONFLICT    0
+#define NO_CONFLICT 1
+
+static int ndselect(int n) {
+  for (int column = 0; column < n; column++) {
+    int pid = fork();
+    if (pid == 0) {
+      return column;
+    }
+    waitpid(pid, NULL, 0);
+  }
+  /* TODO: A loop is missing here that spawns processes and waits for them! */
+  exit(0);
+}
+
+static int conflict(int x1, int y1, int x2, int y2) {
+  return x1 == x2
+    || y1 == y2
+    || x1 + y1 == x2 + y2
+    || x1 - y1 == x2 - y2;
+}
+
+static bool check_conflict(int size, int board[size], int column) {
+  for (int i = 0; i < column; i++) {
+    if (conflict(board[i], i, board[column], column) == 1) return CONFLICT;
+  }
+  return NO_CONFLICT;
+}
+
+static void print_line_sep(int size) {
+  for (int i = 0; i < size; ++i) 
+    printf("+---");
+  printf("+\n");
+}
+
+static void print_board(int size, int board[size]) {
+  for (int i = 0; i < size; ++i) {
+    print_line_sep(size);
+    for (int j = 0; j < size; ++j)
+      printf("|%s", board[i] == j ? " ♕ " : "   ");
+    printf("|\n");
+  }
+  print_line_sep(size);
+  printf("\n");
+}
+
+int main(int argc, char **argv) {
+  if (argc != 2)
+    app_error("Usage: %s [SIZE]", argv[0]);
+
+  int size = atoi(argv[1]);
+
+  if (size < 3 || size > 9)
+    app_error("Give board size in range from 4 to 9!");
+
+  int board[size];
+
+  /* TODO: A loop is missing here that initializes recursive algorithm. */
+  for (int row = 0; row < size; row++) {
+    int column = ndselect(size);
+    board[row] = column;
+    if (check_conflict(size, board, row) == CONFLICT) 
+      exit(0);
+  }
+
+  print_board(size, board);
+
+  return 0;
+}