504:七进制数

src/main/java/leetcode/editor/cn/Base7.java

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+//给定一个整数 num，将其转化为 7 进制，并以字符串形式输出。 
+//
+// 
+//
+// 示例 1: 
+//
+// 
+//输入: num = 100
+//输出: "202"
+// 
+//
+// 示例 2: 
+//
+// 
+//输入: num = -7
+//输出: "-10"
+// 
+//
+// 
+//
+// 提示： 
+//
+// 
+// -10⁷ <= num <= 10⁷ 
+// 
+// Related Topics 数学 👍 148 👎 0
+
+package leetcode.editor.cn;
+
+//504:七进制数
+public class Base7 {
+    public static void main(String[] args) {
+        Solution solution = new Base7().new Solution();
+        // TO TEST
+    }
+
+    //leetcode submit region begin(Prohibit modification and deletion)
+    class Solution {
+        public String convertToBase7(int num) {
+            boolean bl = num < 0;
+            num = Math.abs(num);
+            StringBuilder str = new StringBuilder();
+            while (num >= 7) {
+                str.insert(0, num % 7);
+                num /= 7;
+            }
+            str.insert(0, num);
+            if (bl) {
+                str.insert(0, '-');
+            }
+            return str.toString();
+        }
+    }
+//leetcode submit region end(Prohibit modification and deletion)
+
+}

src/main/java/leetcode/editor/cn/doc/content/Base7.md

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+<p>给定一个整数 <code>num</code>，将其转化为 <strong>7 进制</strong>，并以字符串形式输出。</p>
+
+<p>&nbsp;</p>
+
+<p><strong>示例 1:</strong></p>
+
+<pre>
+<strong>输入:</strong> num = 100
+<strong>输出:</strong> "202"
+</pre>
+
+<p><strong>示例 2:</strong></p>
+
+<pre>
+<strong>输入:</strong> num = -7
+<strong>输出:</strong> "-10"
+</pre>
+
+<p>&nbsp;</p>
+
+<p><strong>提示：</strong></p>
+
+<ul>
+	<li><code>-10<sup>7</sup>&nbsp;&lt;= num &lt;= 10<sup>7</sup></code></li>
+</ul>
+<div><div>Related Topics</div><div><li>数学</li></div></div><br><div><li>👍 148</li><li>👎 0</li></div>