int ,long , long long , __int64类型的范围

首先见测试代码（在g++/gcc下运行）：

#include<iostream>
using namespace std;
int main()
{
	cout<<sizeof(int)<<endl;
	cout<<sizeof(unsigned int)<<endl;
	cout<<sizeof(long)<<endl;
	cout<<sizeof(unsigned long)<<endl;
	cout<<sizeof(long long)<<endl;
	cout<<sizeof(unsigned long long)<<endl;
	cout<<sizeof(__int64)<<endl;
	cout<<sizeof(unsigned __int64)<<endl;
	return 0;
}

　　运行结果为：4 4 4 4 8 8 8 8（均为字节）

有结果可知:int , long , long long , __int64的范围如下：

int   -2147483648～2147483647 

unsigned int   0～4294967295   

long   -2147483648～2147483647

unsigned long 0～4294967295

long long   -9223372036854775808～9223372036854775807

unsigned long long的最大值：18446744073709551615

__int64  -9223372036854775808～9223372036854775807

unsigned __int64的最大值：18446744073709551615