Initial data commit

Task/Knights-tour/JavaScript/knights-tour-1.js

@@ -0,0 +1,215 @@
+class KnightTour {
+ constructor() {
+  this.width = 856;
+  this.height = 856;
+  this.cellCount = 8;
+  this.size = 0;
+  this.knightPiece = "\u2658";
+  this.knightPos = {
+   x: 0,
+   y: 0
+  };
+  this.ctx = null;
+  this.step = this.width / this.cellCount;
+  this.lastTime = 0;
+  this.wait;
+  this.delay;
+  this.success;
+  this.jumps;
+  this.directions = [];
+  this.visited = [];
+  this.path = [];
+  document.getElementById("start").addEventListener("click", () => {
+   this.startHtml();
+  });
+  this.init();
+  this.drawBoard();
+ }
+
+ drawBoard() {
+  let a = false, xx, yy;
+  for (let y = 0; y < this.cellCount; y++) {
+   for (let x = 0; x < this.cellCount; x++) {
+    if (a) {
+     this.ctx.fillStyle = "#607db8";
+    } else {
+     this.ctx.fillStyle = "#aecaf0";
+    }
+    a = !a;
+    xx = x * this.step;
+    yy = y * this.step;
+    this.ctx.fillRect(xx, yy, xx + this.step, yy + this.step);
+   }
+   if (!(this.cellCount & 1)) a = !a;
+  }
+  if (this.path.length) {
+   const s = this.step >> 1;
+   this.ctx.lineWidth = 3;
+   this.ctx.fillStyle = "black";
+   this.ctx.beginPath();
+   this.ctx.moveTo(this.step * this.knightPos.x + s, this.step * this.knightPos.y + s);
+   let a, b, v = this.path.length - 1;
+   for (; v > -1; v--) {
+    a = this.path[v].pos.x * this.step + s;
+    b = this.path[v].pos.y * this.step + s;
+    this.ctx.lineTo(a, b);
+    this.ctx.fillRect(a - 5, b - 5, 10, 10);
+   }
+   this.ctx.stroke();
+  }
+ }
+
+ createMoves(pos) {
+  const possibles = [];
+  let x = 0,
+   y = 0,
+   m = 0,
+   l = this.directions.length;
+  for (; m < l; m++) {
+   x = pos.x + this.directions[m].x;
+   y = pos.y + this.directions[m].y;
+   if (x > -1 && x < this.cellCount && y > -1 && y < this.cellCount && !this.visited[x + y * this.cellCount]) {
+    possibles.push({
+     x,
+     y
+    })
+   }
+  }
+  return possibles;
+ }
+
+ warnsdorff(pos) {
+  const possibles = this.createMoves(pos);
+  if (possibles.length < 1) return [];
+  const moves = [];
+  for (let p = 0, l = possibles.length; p < l; p++) {
+   let ps = this.createMoves(possibles[p]);
+   moves.push({
+    len: ps.length,
+    pos: possibles[p]
+   });
+  }
+  moves.sort((a, b) => {
+   return b.len - a.len;
+  });
+  return moves;
+ }
+
+ startHtml() {
+  this.cellCount = parseInt(document.getElementById("cellCount").value);
+  this.size = Math.floor(this.width / this.cellCount)
+  this.wait = this.delay = parseInt(document.getElementById("delay").value);
+  this.step = this.width / this.cellCount;
+  this.ctx.font = this.size + "px Arial";
+  document.getElementById("log").innerText = "";
+  document.getElementById("path").innerText = "";
+  this.path = [];
+  this.jumps = 1;
+  this.success = true;
+  this.visited = [];
+  const cnt = this.cellCount * this.cellCount;
+  for (let a = 0; a < cnt; a++) {
+   this.visited.push(false);
+  }
+  const kx = parseInt(document.getElementById("knightx").value),
+   ky = parseInt(document.getElementById("knighty").value);
+  this.knightPos = {
+   x: (kx > this.cellCount || kx < 0) ? Math.floor(Math.random() * this.cellCount) : kx,
+   y: (ky > this.cellCount || ky < 0) ? Math.floor(Math.random() * this.cellCount) : ky
+  };
+  this.mainLoop = (time = 0) => {
+   const dif = time - this.lastTime;
+   this.lastTime = time;
+   this.wait -= dif;
+   if (this.wait > 0) {
+    requestAnimationFrame(this.mainLoop);
+    return;
+   }
+   this.wait = this.delay;
+   let moves;
+   if (this.success) {
+    moves = this.warnsdorff(this.knightPos);
+   } else {
+    if (this.path.length > 0) {
+     const path = this.path[this.path.length - 1];
+     moves = path.m;
+     if (moves.length < 1) this.path.pop();
+     this.knightPos = path.pos
+     this.visited[this.knightPos.x + this.knightPos.y * this.cellCount] = false;
+     this.jumps--;
+     this.wait = this.delay;
+    } else {
+     document.getElementById("log").innerText = "Can't find a solution!";
+     return;
+    }
+   }
+   this.drawBoard();
+   const ft = this.step - (this.step >> 3);
+   this.ctx.fillStyle = "#000";
+   this.ctx.fillText(this.knightPiece, this.knightPos.x * this.step, this.knightPos.y * this.step + ft);
+   if (moves.length < 1) {
+    if (this.jumps === this.cellCount * this.cellCount) {
+     document.getElementById("log").innerText = "Tour finished!";
+     let str = "";
+     for (let z of this.path) {
+      str += `${1 + z.pos.x + z.pos.y * this.cellCount}, `;
+     }
+     str += `${1 + this.knightPos.x + this.knightPos.y * this.cellCount}`;
+     document.getElementById("path").innerText = str;
+     return;
+    } else {
+     this.success = false;
+    }
+   } else {
+    this.visited[this.knightPos.x + this.knightPos.y * this.cellCount] = true;
+    const move = moves.pop();
+    this.path.push({
+     pos: this.knightPos,
+     m: moves
+    });
+    this.knightPos = move.pos
+    this.success = true;
+    this.jumps++;
+   }
+   requestAnimationFrame(this.mainLoop);
+  };
+  this.mainLoop();
+ }
+
+ init() {
+  const canvas = document.createElement("canvas");
+  canvas.id = "cv";
+  canvas.width = this.width;
+  canvas.height = this.height;
+  this.ctx = canvas.getContext("2d");
+  document.getElementById("out").appendChild(canvas);
+  this.directions = [{
+    x: -1,
+    y: -2
+   }, {
+    x: -2,
+    y: -1
+   }, {
+    x: 1,
+    y: -2
+   }, {
+    x: 2,
+    y: -1
+   },
+   {
+    x: -1,
+    y: 2
+   }, {
+    x: -2,
+    y: 1
+   }, {
+    x: 1,
+    y: 2
+   }, {
+    x: 2,
+    y: 1
+   }
+  ];
+ }
+}
+new KnightTour();