版权声明:吸吸 https://blog.csdn.net/walk_dog/article/details/79318346
1.公式推导:2 ^ n - 1
2.注意:①.开到 long long型
②.不建议用pow
附代码↓
↓
↓:
#include<bits/stdc++.h>
using namespace std;
int main( )
{
int n;
long long Sum = 1;
scanf("%d", &n);
for(int i = 1; i <= n; i++)
{
Sum *= 2;
}
printf("%lld", Sum - 1);
}
using namespace std;
int main( )
{
int n;
long long Sum = 1;
scanf("%d", &n);
for(int i = 1; i <= n; i++)
{
Sum *= 2;
}
printf("%lld", Sum - 1);
}