Add Binary
描述
Given two binary strings, return their sum (also a binary string).
For example,
a = “11”
b = “1”
Return “100”.
题意
略
分析
略
题解
[C/C++]:
[Python]:
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char* addBinary(char* a, char* b) {
char *ret;
int la,lb,lr;
int i,j,k;
int carry = 0;
int value;
la = strlen(a);
lb = strlen(b);
lr = (la > lb ? la : lb) + 2;
ret = (char *)malloc(sizeof(char) * lr);
ret[lr-1] = 0;
k = lr-2;
i = la - 1;
j = lb - 1;
while(i >= 0 && j >= 0){
value = (a[i--] - '0') + (b[j--] - '0') + carry;
carry = value / 2;
value %= 2;
ret[k--] = '0' + value;
}
if(j >= 0){
i = j;
a = b;
}
while(i >= 0){
value = (a[i--] - '0') + carry;
carry = value / 2;
value %= 2;
ret[k--] = '0' + value;
}
if(carry)
ret[k--] = '1';
return ret + k + 1;
}
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class Solution(object):
def addBinary(self, a, b):
"""
:type a: str
:type b: str
:rtype: str
"""
indexa = len(a) - 1
indexb = len(b) - 1
res = ''
carry = 0
while indexa >= 0 or indexb >= 0:
x = int(a[indexa]) if indexa >= 0 else 0
y = int(b[indexb]) if indexb >= 0 else 0
value = x + y + carry
carry = value // 2
value = value % 2
res = str(value) + res
indexa, indexb = indexa - 1, indexb - 1
if carry == 1:
res = '1' + res
return res
