Shifting Letters

[wupangyen]

Summary:

Start from the back.

for example if the given s is abc and the shifts are [3,6,9]

if we start from the last char of s which is c

it need to be shifted by 9 letters away , so on next char b will be shifted 9 + 6 letters away

and lastly char a will be shifted 9 + 6 + 3 letters away

[wupangyen]