fix path calculation

src/js/index.js

@@ -260,26 +260,29 @@ function calculateDistance(lat1, lon1, lat2, lon2) {
     return d;
 }
 
+function getRandomInt(min, max) {
+    min = Math.ceil(min);
+    max = Math.floor(max);
+    return Math.floor(Math.random() * (max - min + 1)) + min;
+}
+
 function shuffle(array, fix_start_point = true, fix_end_point = true) {
-    let currentIndex = array.length;
+    let currentIndex = array.length - 1;
     if (fix_end_point) {
-        currentIndex = array.length - 1;
+        currentIndex = array.length - 2;
     }
     let start_index = 0;
     if (fix_start_point) {
         start_index = 1;
     }
-    // While there remain elements to shuffle...
-    while (currentIndex != start_index) {
-
-        // Pick a remaining element...
-        let randomIndex = Math.floor(Math.random() * currentIndex);
-        currentIndex--;
-
+    while (currentIndex !== start_index) {
+        let right = currentIndex;
+        let left = getRandomInt(start_index, currentIndex);
         // And swap it with the current element.
-        [array[currentIndex], array[randomIndex]] = [
-            array[randomIndex], array[currentIndex]
+        [array[left], array[right]] = [
+            array[right], array[left]
         ];
+        currentIndex--;
     }
 }
 
@@ -351,6 +354,7 @@ function recalculateWaypoints(waypoints) {
             // Три точки, старт, стоп и промежуточная выводим без расчета
             showTravelPoints([waypoints[0].id, waypoints[1].id, waypoints[2].id]);
         } else {
+
             // применяем лучшие поиск из 200.000 лучших вариантов (9! = 362880, берем такого порядка число чтобы не грузить браузер расчетами)
             let path_indexes = stochasticPathFind(waypoints, true, true);
             showTravelPoints(path_indexes);
@@ -360,7 +364,6 @@ function recalculateWaypoints(waypoints) {
 
 $(() => {
     waypoints.loadData();
-
     initMap();
     initRegionDropDown();
     initRecalculateWaypointsButton();