在树形图中设置树形图的值？

Question

请耐心等待，我一直在网上搜索，试图找到正在发生的轻微问题的正确语法。你将如何在树形图中设置树形图？

的地图实例变量是：

private final TreeMap<Integer,TreeMap<Integer,Double>> matrix; 

/** 
* Change the value at a given position. 
* If the position is not in the matrix (i.e., i is not between 0 and rows-1 
* and j is not between 0 and cols-1), then don't change anything. 
* 
* @param i The row. 
* @param j The column. 
* @param v The new value. 
*/ 
public void set(int i, int j, double v) { 
    if (matrix.containsKey(i) && matrix.containsValue(j) == true) { 
     matrix.remove(j); // Is this needed? 
     matrix.put(i<j,v>); // ERROR: not right syntax for this 
    } 
} // end of set method 

Answer 1

这是你在找什么？

matrix.get(i).put(j, v); 

Answer 2

private final TreeMap<Integer,TreeMap<Integer,Double>> matrix; 

您可以将值不分配给它的实例是宣布为最终，除了在您声明的声明外：

public final TreeMap<Integer,TreeMap<Integer,Double>> matrix = new TreeMap<>(); 

那么你应该能够put，getTreeMap从matrix像往常一样：

matrix.put(1, new TreeMap<Integer, Double>()); 
matrix.get(1).put(1, 1.23);