Int~long long indicates the maximum and minimum number

int Occupy 32 When a , The maximum value that can be assigned is ：2147483647. That is to say 0x7fffffff.

In a computer, we specify that the highest bit is the sign bit . by 0 Yes , by 1 negative . So the highest order is not allowed to participate in the calculation .

long long The maximum of ：9223372036854775807 
long long The minimum value of ：-9223372036854775808 

Commonly used for the selection of numeric types