字符怎么转化数字 就是a(字符型)转化为数字1(整型) 然后依次排下去 26个英文字母 有没有强制执行a(字符型)=1(整型)的语句
java的哈弗曼树编码译码 已经把哈弗曼树写出来了 然后要输入字符串 编码 只要能让字符串里的字母对号入座 就行了 但是我不会弄 望各位大大指点一下
java的哈弗曼树编码译码 已经把哈弗曼树写出来了 然后要输入字符串 编码 只要能让字符串里的字母对号入座 就行了 但是我不会弄 望各位大大指点一下
{
int[] bit; //数组
int start; //编码的起始下标
int weight; //字符的权值
public Code(int n)
{
bit = new int[n];
start = n - 1;
}
}
class HaffNode //哈夫曼树的结点类
{
int weight; //权值
int flag; //标记
int parent; //双亲结点下标
int leftChild; //左孩子下标
int rightChild; //右孩子下标
public HaffNode()
{
}
}
class HaffmanTree
{
static final int maxValue = 10000; //最大权值
private int nodeNum; //叶结点个数
public HaffmanTree(int n)
{
nodeNum = n;
}
public void haffman(int[] weight, HaffNode[] node) //构造权值为weight的哈夫曼树haffTree
{
int m1, m2, x1, x2;
int n = nodeNum;
//哈夫曼树haffTree初始化。n个叶结点的哈夫曼树共有2n-1个结点
for(int i = 0; i < 2 * n - 1; i ++)
{
HaffNode temp = new HaffNode();
if(i < n)
temp.weight = weight[i];
else
temp.weight = 0;
temp.parent = 0;
temp.flag = 0;
temp.leftChild = -1;
temp.rightChild = -1;
node[i] = temp;
}
//构造哈夫曼树haffTree的n-1个非叶结点
for(int i = 0; i < n - 1; i++)
{
m1 = m2 = maxValue;
x1 = x2 = 0;
for(int j = 0; j < n + i; j ++)
{
if(node[j].weight < m1 && node[j].flag == 0)
{
m2 = m1;
x2 = x1;
m1 = node[j].weight;
x1 = j;
}
else if(node[j].weight < m2 && node[j].flag == 0)
{
m2 = node[j].weight;
x2 = j;
}
}
//将找出的两棵权值最小的子树合并为一棵子树
node[x1].parent = n+i;
node[x2].parent = n+i;
node[x1].flag = 1;
node[x2].flag = 1;
node[n+i].weight = node[x1].weight+node[x2].weight;
node[n+i].leftChild = x1;
node[n+i].rightChild = x2;
}
}
public void haffmanCode(HaffNode[] node, Code[] haffCode)
{
//由哈夫曼树haffTree构造哈夫曼编码haffCode
int n = nodeNum;
Code cd = new Code(n);
int child, parent;
//求n个叶结点的哈夫曼编码
for(int i = 0; i < n; i ++)
{
cd.start = n - 1; //不等长编码的最后一位为n-1
cd.weight = node[i].weight; //取得编码对应的权值
child = i;
parent = node[child].parent;
while(parent != 0)
{
//由叶结点向上直到根结点循环
if(node[parent].leftChild == child)
cd.bit[cd.start] = 0; //左孩子结点编码0
else
cd.bit[cd.start] = 1; //右孩子结点编码1
cd.start --;
child = parent;
parent = node[child].parent;
}
Code temp = new Code(n);
//保存叶结点的编码和不等长编码的起始位
for(int j = cd.start+1; j < n; j++)
temp.bit[j] = cd.bit[j];
temp.start = cd.start;
temp.weight = cd.weight;
haffCode[i] = temp;
}
}
}
public class Huffman_Tree
{
public static void main(String[] args)
{
int n = 26;
HaffmanTree myHaff = new HaffmanTree(n);
int[] weight = {64,13,22,32,103,21,15,47,57,1,5,32,20,57,63,15,1,48,51,80,23,8,18,1,16,1};
HaffNode[] node = new HaffNode[2 * n + 1];
Code[] haffCode = new Code[n];
String[] zimu = {"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"};
int[] target = {19,7,8,18,15,17,14,6,17,0,12,8,18,12,24,5,0,21,14,17,8,19,5};
myHaff.haffman(weight, node);
myHaff.haffmanCode(node, haffCode);
//输出每个叶结点的哈夫曼编码
System.out.print("从A到Z的编码依次为:");
System.out.println();
for(int i = 0; i < n; i ++)
{
System.out.print(zimu[i]+":Weight = " + haffCode[i].weight + " Code = ");
for(int j = haffCode[i].start + 1; j < n; j ++)
System.out.print(haffCode[i].bit[j]);
System.out.println();
}
System.out.print("“THIS PROGRAM IS MY FAVORITE”编码为:");
System.out.println();
for(int i = 0; i < 23; i ++)
{
int j=target[i];
for(int k = haffCode[j].start + 1; k < n; k ++)
System.out.print(haffCode[j].bit[k]);
}
}
}
String s="a";
System.out.println(s.hashCode());
}
因为在asc表里，字符确实是顺序排列的。
只考虑小写字母，b-a=1
那你所要做的就仅仅是把字符转换成int型了，然后计算相对字符a的偏移值
public static int trans(char c){
int t = c-'a'+1;
return t;
}
String str1 = "string";
byte[] byteArr = str1.getBytes();
//然后循环此数组，过程中调用byte的intValue()方法。
//是这意思？
int i = Integer.parseInt(s);需要try catch
char ch='b';
int num=ch-'a'+1;
本来 System.out.print(zimu[i]+":Weight = " + haffCode[i].weight + " Code = "); 是输出第i个结点的权值
然后我改成 System.out.print(zimu[a]+":Weight = " + haffCode[a].weight + " Code = "); 把上面的计数i改成了c 这样它变成第3个结点的权值 不知道可以不可以
若不可以 介绍我一种方法 将输入一段英文字符 对应到我对英文字母的编码上面去
就是说 我现在有顺序的输入了 a-z 的权值 经过我的程序运算后 得到了顺序的 权值 = 1,2,3,...,n 对应的 编码 然后我现在输入一段字符串 ab 我有之前的编码 a对应一个01 b对应一个00 所以我的ab编码后是0100 这样 我要怎么做才行? 上面的数字都不是真实的
public static void main(String[] args){
int[] charNum = new int[26];
char c = 'a';
for(int i = 0; i < charNum.length; i ++){
charNum[i] = (int)(c - 'a') + 1;
c++;
System.out.print(charNum[i] + " ");
}
}
}