public:

int divide(long long dividend, long long divisor) { // dividend and divisor must be changed into the type of long long from int

bool negative = false;

if((dividend<0&&divisor>0)||(dividend>0&&divisor<0))

negative=true;

if(dividend==0)

return 0;

if(divisor==0)

return NULL;

if(dividend<0) dividend*=-1;

if(divisor<0) divisor*=-1;

int i=0;

while((divisor<<i)<=dividend)

{

i++;

}

i--;

int ans=0;

while(dividend>=divisor)

{

if(dividend-(divisor<<i)>=0)

{

dividend=dividend-(divisor<<i);

ans+=(1<<i);

}

i--;

}

if(negative==true) ans*=-1;

return ans;

}

int divide(long long dividend, long long divisor) {

// Start typing your C/C++ solution below

// DO NOT write int main() function

if(dividend == 0)

return 0;

int negative = 0;

if(dividend < 0)

{

dividend *= -1;

negative = (negative + 1) % 2;

}

if(divisor < 0)

{

divisor *= -1;

negative = (negative + 1) % 2;

}

int i = 0;

while(divisor << i <= dividend)

{

++i;

}

--i;

int ans = 0;

while(dividend >= divisor)

{

if(dividend - (divisor << i) >= 0)

{

dividend -= (divisor << i);

ans += 1 << i;

}

--i;

}

if(negative == 0)

return ans;

else

return -1 * ans;

}