后序深度搜索

Question

如果我有像示出的对象：

var data = { pages: [{ key: 1, pages: [{ key: 2, pages: [{ key: 3 }] }, { key: 4, pages: [{ key: 5 }] }] }] }; 

所得阵列应该是：[3,5,2,4,1]

Answer 1

var data = { 
 
    pages: [{ 
 
    key: 1, 
 
    pages: [{ 
 
     key: 2, 
 
     pages: [{ 
 
     key: 3 
 
     }] 
 
    }, { 
 
     key: 4, 
 
     pages: [{ 
 
     key: 5 
 
     }] 
 
    }] 
 
    }] 
 
}; 
 

 
var postOrderObj = {}; 
 

 
function getLevels(data) { 
 

 
    for (var i = 0; i < data.pages.length; i++) { 
 
    var obj = data.pages[i]; 
 

 
    if (postOrderObj[data.level]) { 
 
     postOrderObj[data.level].push(obj.key); 
 

 
     if (obj.pages) { 
 
     getLevels({ 
 
      pages: obj.pages, 
 
      level: data.level + 1, 
 
      parentLevel: data.level 
 
     }); 
 
     } 
 
    } else { 
 
     if (data.parentLevel) { 
 
     data.level = data.parentLevel + 1; 
 
     } else { 
 
     data.parentLevel = 0; 
 
     data.level = data.parentLevel + 1; 
 
     } 
 

 
     postOrderObj[data.level] = [obj.key]; 
 

 
     if (obj.pages) { 
 
     getLevels({ 
 
      pages: obj.pages, 
 
      level: data.level + 1, 
 
      parentLevel: data.level 
 
     }); 
 
     } 
 
    } 
 
    } 
 
} 
 

 
function getPostOrder(postOrderObj) { 
 
    var postOrderArry = []; 
 
    for (var key in postOrderObj) { 
 
    var levelArry = postOrderObj[key]; 
 
    for (var i = levelArry.length - 1; i >= 0; i--) { 
 
     postOrderArry.unshift(levelArry[i]); 
 
    } 
 
    } 
 
    return postOrderArry; 
 
} 
 

 
getLevels(data); 
 
var result = getPostOrder(postOrderObj); 
 
console.log(result);