feat: add Darts exercise

Author: rmzmrnn

exercism/darts/darts.c

@@ -0,0 +1,28 @@
+/*
+ * <--Introduction-->
+ * Refer to this exercise for full details:
+ * https://exercism.org/tracks/c/exercises/darts
+ *   
+*/
+
+#include "darts.h"
+
+unsigned int score(coordinate_t landing_position){
+    
+    // We used the Pythagorean theorem to get the radius by using the two coordinates:
+    // 1. landing_position.x
+    // 2. landing_position.y
+    float radius = sqrt(pow(landing_position.x, 2) + pow(landing_position.y, 2));
+
+    /*
+     * Note: Interval notation is used to show the range of the radius to
+     * determine the score
+     *
+     * If radius is [0, 1]    , return a score of 10
+     * If radius is (1, 5]    , return a score of 5
+     * If radius is (5, 10]   , return a score of 1
+     * If radius is (-inf, 0) or (10, +inf), return a score of 0
+     * 
+     */
+    return radius >= 0 && radius <= 1 ? 10 : radius > 1 && radius <= 5 ? 5 : radius > 5 && radius <= 10 ? 1 : 0;
+}

exercism/darts/darts.h

@@ -0,0 +1,15 @@
+#ifndef DARTS_H
+#define DARTS_H
+
+#include <math.h>
+#include <stdlib.h>
+
+typedef struct
+{
+    float x;
+    float y;
+} coordinate_t;
+
+unsigned int score(coordinate_t landing_position);
+
+#endif