#1622
Fancy Sequence
grandmaster · 2250 · lc hard +32 · 18.6% accepted · 388 likes · top 1%
Description
Design a Fancy class for a dynamically modified sequence. Implement:
- Fancy() initializes an empty sequence.
- void append(val) appends val to the sequence.
- void addAll(inc) adds inc to every element in the sequence.
- void multAll(m) multiplies every element by m.
- int getIndex(idx) returns the element at index idx modulo 109 + 7, or -1 if the index is out of range.
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]
Example 2:
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
Code
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