Package g1601_1700.s1622_fancy_sequence

Class Fancy

java.lang.Object
g1601_1700.s1622_fancy_sequence.Fancy
public class Fancy extends java.lang.Object
1622 - Fancy Sequence.

Hard

Write an API that generates fancy sequences using the append, addAll, and multAll operations.

Implement the Fancy class:

  • Fancy() Initializes the object with an empty sequence.
  • void append(val) Appends an integer val to the end of the sequence.
  • void addAll(inc) Increments all existing values in the sequence by an integer inc.
  • void multAll(m) Multiplies all existing values in the sequence by an integer m.
  • int getIndex(idx) Gets the current value at index idx (0-indexed) of the sequence modulo 109 + 7. If the index is greater or equal than the length of the sequence, return -1.

Example 1:

Input [“Fancy”, “append”, “addAll”, “append”, “multAll”, “getIndex”, “addAll”, “append”, “multAll”, “getIndex”, “getIndex”, “getIndex”] [ [], [2], [3], [7], [2], [0], [3], [10], [2], [0], [1], [2]]

Output: [null, null, null, null, null, 10, null, null, null, 26, 34, 20]

Explanation:

Fancy fancy = new Fancy();

fancy.append(2); // fancy sequence: [2]

fancy.addAll(3); // fancy sequence: [2+3] -> [5]

fancy.append(7); // fancy sequence: [5, 7]

fancy.multAll(2); // fancy sequence: [5*2, 7*2] -> [10, 14]

fancy.getIndex(0); // return 10

fancy.addAll(3); // fancy sequence: [10+3, 14+3] -> [13, 17]

fancy.append(10); // fancy sequence: [13, 17, 10]

fancy.multAll(2); // fancy sequence: [13*2, 17*2, 10*2] -> [26, 34, 20]

fancy.getIndex(0); // return 26

fancy.getIndex(1); // return 34

fancy.getIndex(2); // return 20

Constraints:

  • 1 <= val, inc, m <= 100
  • 0 <= idx <= 105
  • At most 105 calls total will be made to append, addAll, multAll, and getIndex.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Fancy()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    addAll(int inc)
     
    void
    append(int val)
     
    int
    getIndex(int idx)
     
    void
    multAll(int m)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Fancy

      public Fancy()

  • Method Details

    • append

      public void append(int val)

    • addAll

      public void addAll(int inc)

    • multAll

      public void multAll(int m)

    • getIndex

      public int getIndex(int idx)