float point exception, waiting for debugging

src/position.cc

@@ -0,0 +1,52 @@
+#include "position.h"
+
+position::position(): x{0}, y{0} {}
+
+position::position(int nx, int ny): x{nx}, y{ny} {}
+
+position position::operator+(const position &other) const {
+        position result{x + other.x, y + other.y};
+        return result;
+}
+
+position &position::operator=(const position &other) {
+        x = other.x;
+        y = other.y;
+        return *this;
+}
+
+position &position::operator+=(const position &other) {
+        return *this = *this + other;
+}
+
+bool position::operator==(const position &other) const {
+        return x == other.x && y == other.y;
+}
+
+bool position::operator!=(const position &other) const {
+        return x != other.x || y != other.y;
+}
+
+bool position::operator<(const position &other) const {
+        return y < other.y || x < other.x;
+}
+
+size_t find(const std::vector<position> &sorted_list,
+            const position &target) {
+        int l = 0;
+        int r = sorted_list.size() - 1;
+
+        while (l <= r) {
+                int mid = l + (l + r) / 2;
+
+                if (target == sorted_list[mid])
+                        return mid;
+
+                if (target < sorted_list[mid])
+                        l = mid + 1;
+                else
+                        r = mid - 1;
+        }
+
+        return sorted_list.size();
+}