朝雨辰河 @ 2019-07-31 20:30:30
using namespace std;
int a[1000002],b[1000002],ans;
void cmp(int x,int y)
{
int p,i,j,k;
if(x>=y) return ;
p=(x+y)/2;
cmp(x,p);
cmp(p+1,y);
i=x;
j=p+1;
k=x;
while(i<=p&&j<=y)
if(a[i]<=a[j])
b[k++]=a[i++];
else b[k++]=a[j++],ans+=p-i+1;
while(i<=p)
b[k++]=a[i++];
while(j<=y)
b[k++]=a[j++];
for(i=x;i<=y;i++)
a[i]=b[i];
}
int main()
{
int n,i;
cin>>n;
for(i=1;i<=n;i++)
cin>>a[i];
cmp(1,n);
cout<<ans;
}
by 樱花飞舞 @ 2019-07-31 20:34:19
你不会用Markdown吗？
这张图片我发了快十次了
by 朝雨辰河 @ 2019-07-31 20:36:00
#include<bits/stdc++.h>
using namespace std;
int a[1000002],b[1000002],ans;
void cmp(int x,int y)
{
int p,i,j,k;
if(x>=y) return ;
p=(x+y)/2;
cmp(x,p);
cmp(p+1,y);
i=x;
j=p+1;
k=x;
while(i<=p&&j<=y)
if(a[i]<=a[j])
b[k++]=a[i++];
else b[k++]=a[j++],ans+=p-i+1;
while(i<=p)
b[k++]=a[i++];
while(j<=y)
b[k++]=a[j++];
for(i=x;i<=y;i++)
a[i]=b[i];
}
int main()
{
int n,i;
cin>>n;
for(i=1;i<=n;i++)
cin>>a[i];
cmp(1,n);
cout<<ans;
}
by Alioth_ @ 2019-07-31 20:43:43
你不会缩进吗？
by 朝雨辰河 @ 2019-07-31 20:50:12
OK啦
by gx123 @ 2019-08-14 17:59:45
改为long long吧