hdu 1394

OJ

#include <iostream>#include <cstdio>#include <cstdlib>#include <algorithm>#include <vector>#include <map>#include <set>#include <string>#include <cstring>#include <list>#include <queue>#include <stack>#include <cmath>using namespace std;#define PF(x) (scanf("%d",&x))#define PT(x,y) (scanf("%d%d",&x,&y))#define PR(x) (printf("%d\n",x))#define PRT(x,y)(printf("%d %d\n",x,y))#define M 5005int n;int ar[M];int a[M];int minx(int a,int b){return a>b?b:a;}int lowbit(int x){return x&(-x);}void  add(int x,int c){for(;x<M;x+=lowbit(x)){ar[x] += c;}}int sum(int x){int s = 0;for(;x;x-=lowbit(x))s += ar[x];return s;}void init(){while(scanf("%d",&n)!=EOF){int ans = 0;memset(ar,0,sizeof(ar));for(int i=0;i<n;i++){int x;PF(x);a[i] = x;ans += (sum(n)-sum(x+1));add(x+1,1);}int t = ans;for(int i=0;i<n;i++){t = t +n-1-a[i] - (a[i]);ans = minx(ans,t);}PR(ans);}return ;}int main(){init();return 0;}