Detailed explanation of CocosCreator Huarongdao digital puzzle

//Loop through the solution while (true) {
    let steps: Array<any> = [];
    let lastGrad: Array<any> = this.mMapData[this.mMapData.length - 1];
    console.log(lastGrad.length);
    //Traverse all the results in the last gradient and solve the next step for (let i = 0; i < lastGrad.length; i++) {
        let matrix = lastGrad[i]["matrix"];
        let answer = lastGrad[i]["answer"];
        let result: Array<any> = this.move(matrix, answer, steps);
        if (result) {
            console.log("Result:", result);
            resolve(result);
            return;
        }
    }

    if(steps.length<=0){
        console.log("Query result failed, ");
        resolve(null);
        return;
    }
    this.mMapData.push(steps);
}

private move(matrix: Array<number>, answer: Array<any>, steps: Array<any>): Array<any> {
    for (let i = 0; i < matrix.length; i++) {
        if (matrix[i] != -1) { //Not an empty space, check whether it can be moved, and get the movable result //Check whether it can be moved up, down, left, and right,
            let result0: Array<any> = this.moveUp(i, matrix, answer, steps);
            let result1: Array<any> = this.moveDown(i, matrix, answer, steps);
            let result2: Array<any> = this.moveLeft(i, matrix, answer, steps);
            let result3: Array<any> = this.moveRight(i, matrix, answer, steps);

            if (result1) {
                return result1;
            }
            if (result2) {
                return result2;
            }
            if (result0) {
                return result0;
            }
            if (result3) {
                return result3;
            }
        }
    }
    return null;
}

private moveRight(i: number, matrix: Array<number>, answer: Array<any>, steps: Array<any>): Array<any> {
    let line: number = i % this.mLine;
    let row: number = Math.floor(i / this.mLine);
    if (line + 1 >= this.mLine) return null; //Out of bounds let targetIndex: number = row * this.mLine + (line + 1);
    if ( matrix[targetIndex] != -1) return null; //Not movable //Move //Move //Copy the new array for modification let newMatrix: Array<number> = JSON.parse(JSON.stringify(matrix));
    let newAnswer: Array<any> = JSON.parse(JSON.stringify(answer));
    //Exchange positions let temp: number = newMatrix[i];
    newMatrix[i] = newMatrix[targetIndex];
    newMatrix[targetIndex] = temp;
    newAnswer.push({ "index": i, "dic": 3 });

    if (this.checkIsExist(newMatrix)) {
        return null;
    }

    if (this.checkPass(newMatrix)) {
        return newAnswer;
    }
    let step: any = {};
    step["matrix"] = newMatrix;
    step["answer"] = newAnswer;
    steps.push(step);
}
/**
 * Check if it is cleared*/
private checkPass(matrix: Array<number>): boolean {
    if (matrix[this.mRow * this.mLine - 1] != -1) return false;
    for (let i = 0; i < this.mRow * this.mLine - 1; i++) {
        if (matrix[i] != i + 1) {
            return false;
        }
    }
    console.log(matrix)
    return true;
}
/**
 * Check if it is repeated */
private checkIsExist(matrix): boolean {
    if (this.mMapMatrixS[JSON.stringify(matrix)]) {
        return true;
    }
    this.mMapMatrixS[JSON.stringify(matrix)] = "1";
    return false;
}