long int
Pow( long int x, unsigned int n ) { // 求幂运算
int y, mul, temp;
if( n == 0 )
return 1;
if( n == 1 )
return x;
y = x, mul = 1;
while( n > 1 ) {
if( n % 2 == 0 ) {
temp = y * y;
y = temp;
n = n / 2;
}
else {
mul = mul * y;
temp = y * y;
y = temp;
n = n / 2;
}
}
y = mul * y;
return y;
}