Calculate the sum of two integers a and b, but you are not allowed to use the Operator +
and -
.
Example:Given a = 1 and b = 2, return 3.
Python solution with no "+-*/%", completely bit manipulation guaranteedclass Solution(object): def getSum(self, a, b): """ :type a: int :type b: int :rtype: int """ # 32 bits integer max MAX = 0x7FFFFFFF # 32 bits interger min MIN = 0x80000000 # mask to get last 32 bits mask = 0xFFFFFFFF while b != 0: # ^ get different bits and & gets double 1s, << moves carry a, b = (a ^ b) & mask, ((a & b) << 1) & mask # if a is negative, get a's 32 bits complement positive first # then get 32-bit positive's Python complement negative return a if a <= MAX else ~(a ^ mask)class Solution {public: int getSum(int a, int b) { int sum=a; while(b!=0){ sum = a^b; //add different bits b = (a&b)<<1; //left same bits a = sum; } return sum; }};
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