66. plus one

Author: jiofeng

66PlusOne/PlusOne.java

@@ -0,0 +1,37 @@
+/**
+ * @author jiofeng
+ * @date 2020/3/1
+ */
+public class PlusOne {
+    public static void main(String[] args) {
+        int[] digits = {9, 8, 9};
+        for (int digit : new PlusOneSolution().plusOne(digits)) {
+            System.out.println(digit);
+        }
+    }
+}
+
+class PlusOneSolution {
+    public int[] plusOne(int[] digits) {
+        boolean carryFlag = true;
+        for (int i = digits.length - 1; i >= 0; i--) {
+            if (carryFlag) {
+                digits[i] = ++digits[i];
+                carryFlag = false;
+            }
+            if (digits[i] >= 10) {
+                digits[i] %= 10;
+                carryFlag = true;
+            }
+            if (!carryFlag) {
+                break;
+            }
+        }
+        if (carryFlag) {
+            int[] newDigits = new int[digits.length + 1];
+            newDigits[0] = 1;
+            return newDigits;
+        }
+        return digits;
+    }
+}