273:整数转换英文表示

src/main/java/leetcode/editor/cn/IntegerToEnglishWords.java

@@ -0,0 +1,96 @@
+//将非负整数 num 转换为其对应的英文表示。 
+//
+// 
+//
+// 示例 1： 
+//
+// 
+//输入：num = 123
+//输出："One Hundred Twenty Three"
+// 
+//
+// 示例 2： 
+//
+// 
+//输入：num = 12345
+//输出："Twelve Thousand Three Hundred Forty Five"
+// 
+//
+// 示例 3： 
+//
+// 
+//输入：num = 1234567
+//输出："One Million Two Hundred Thirty Four Thousand Five Hundred Sixty Seven"
+// 
+//
+// 示例 4： 
+//
+// 
+//输入：num = 1234567891
+//输出："One Billion Two Hundred Thirty Four Million Five Hundred Sixty Seven 
+//Thousand Eight Hundred Ninety One"
+// 
+//
+// 
+//
+// 提示： 
+//
+// 
+// 0 <= num <= 2³¹ - 1 
+// 
+// Related Topics 递归 数学 字符串 👍 198 👎 0
+
+package leetcode.editor.cn;
+
+//273:整数转换英文表示
+class IntegerToEnglishWords {
+    public static void main(String[] args) {
+        //测试代码
+        Solution solution = new IntegerToEnglishWords().new Solution();
+    }
+
+    //力扣代码
+    //leetcode submit region begin(Prohibit modification and deletion)
+    class Solution {
+        String[] singles = {"", "One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine"};
+        String[] teens = {"Ten", "Eleven", "Twelve", "Thirteen", "Fourteen", "Fifteen", "Sixteen", "Seventeen", "Eighteen", "Nineteen"};
+        String[] tens = {"", "Ten", "Twenty", "Thirty", "Forty", "Fifty", "Sixty", "Seventy", "Eighty", "Ninety"};
+        String[] thousands = {"", "Thousand", "Million", "Billion"};
+
+        public String numberToWords(int num) {
+            if (num == 0) {
+                return "Zero";
+            }
+            StringBuffer sb = new StringBuffer();
+            for (int i = 3, unit = 1000000000; i >= 0; i--, unit /= 1000) {
+                int curNum = num / unit;
+                if (curNum != 0) {
+                    num -= curNum * unit;
+                    StringBuffer curr = new StringBuffer();
+                    recursion(curr, curNum);
+                    curr.append(thousands[i]).append(" ");
+                    sb.append(curr);
+                }
+            }
+            return sb.toString().trim();
+        }
+
+        public void recursion(StringBuffer curr, int num) {
+            if (num == 0) {
+                return;
+            } else if (num < 10) {
+                curr.append(singles[num]).append(" ");
+            } else if (num < 20) {
+                curr.append(teens[num - 10]).append(" ");
+            } else if (num < 100) {
+                curr.append(tens[num / 10]).append(" ");
+                recursion(curr, num % 10);
+            } else {
+                curr.append(singles[num / 100]).append(" Hundred ");
+                recursion(curr, num % 100);
+            }
+        }
+    }
+//leetcode submit region end(Prohibit modification and deletion)
+
+}

src/main/java/leetcode/editor/cn/doc/content/IntegerToEnglishWords.md

@@ -0,0 +1,40 @@
+<p>将非负整数 <code>num</code> 转换为其对应的英文表示。</p>
+
+<p> </p>
+
+<p><strong>示例 1：</strong></p>
+
+<pre>
+<strong>输入：</strong>num = 123
+<strong>输出：</strong>"One Hundred Twenty Three"
+</pre>
+
+<p><strong>示例 2：</strong></p>
+
+<pre>
+<strong>输入：</strong>num = 12345
+<strong>输出：</strong>"Twelve Thousand Three Hundred Forty Five"
+</pre>
+
+<p><strong>示例 3：</strong></p>
+
+<pre>
+<strong>输入：</strong>num = 1234567
+<strong>输出：</strong>"One Million Two Hundred Thirty Four Thousand Five Hundred Sixty Seven"
+</pre>
+
+<p><strong>示例 4：</strong></p>
+
+<pre>
+<strong>输入：</strong>num = 1234567891
+<strong>输出：</strong>"One Billion Two Hundred Thirty Four Million Five Hundred Sixty Seven Thousand Eight Hundred Ninety One"
+</pre>
+
+<p> </p>
+
+<p><strong>提示：</strong></p>
+
+<ul>
+	<li><code>0 <= num <= 2<sup>31</sup> - 1</code></li>
+</ul>
+<div><div>Related Topics</div><div><li>递归</li><li>数学</li><li>字符串</li></div></div><br><div><li>👍 198</li><li>👎 0</li></div>