POJ1007 DNA Sorting

Posted 2020-11-02 pigba

题意:给你一些字符串，字符串的权值是逆序对个数，对这个权值排序字符串

对每个字符串归并排序求逆序对即可（我归并排序写跪了就很捞）

#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstring>
using namespace std;
const int N=202;
string b[N],s;
int c[N],p[N],cnt;
int n,m;
struct name
{
  int p;
  string a;
  friend inline bool operator < (const name &x,const name &y)
  {
    return x.p<y.p;
  }
}t[N];
void merge_sort(int l,int r)
{
  int mid,i,j,tmp;
  if(l==r) return ;
  mid=l+r>>1;
  merge_sort(l,mid);
  merge_sort(mid+1,r);
  tmp=l;
  for(i=l,j=mid+1;i<=mid&&j<=r;)
    {
      if(s[i]>s[j]) c[tmp++]=s[j++],cnt+=mid-i+1;
      else c[tmp++]=s[i++];
    }
  if(j<=r) for(;j<=r;j++) c[tmp++]=s[j];
  else for(;i<=mid;i++) c[tmp++]=s[i];
  for(i=l;i<=r;i++) s[i]=c[i];
}
int calc(int x)
{
  s=t[x].a;
  cnt=0;
  merge_sort(0,n-1);
  t[x].p=cnt;
}
int main()
{
  scanf("%d%d",&n,&m);
  for(int i=1;i<=m;i++) cin>>t[i].a,calc(i);
  sort(t+1,t+m+1);
  for(int i=1;i<=m;i++) cout<<t[i].a<<endl;
  return 0;
}