1 // File Name: a.cpp 2 // Author: darkdream 3 // Created Time: 2014年08月05日 星期二 12时05分09秒 4  5 #include<vector> 6 #include<list> 7 #include<map> 8 #include<set> 9 #include<deque>10 #include<stack>11 #include<bitset>12 #include<algorithm>13 #include<functional>14 #include<numeric>15 #include<utility>16 #include<sstream>17 #include<iostream>18 #include<iomanip>19 #include<cstdio>20 #include<cmath>21 #include<cstdlib>22 #include<cstring>23 #include<ctime>24 #define LL long long25 26 using namespace std;27 int n , k ; 28 LL sum = 0 ; 29 int lowbit(int x)30 {31     return x&(-x);32 }33 struct node{34     int num, s,rs ; 35 }a[100005];36 int num[100005];37 int getsum(int x){38     int sum = 0 ;39     while(x >= 1)40     {41         sum += num[x];42         x -= lowbit(x);43     }44     return sum ; 45 }46 void update(int x)47 {48     while(x <= n )49     {50         num[x] ++ ; 51         x += lowbit(x);52     }53     return; 54 }55 int cmp(node x ,node y )56 {57     return x.num < y.num;58 }59 int cmp1(node x, node y)60 {61     return x.s < y.s; 62 }63 int main(){64     while(scanf("%d %d",&n,&k)!= EOF)65     {66         memset(num,0,sizeof(num));67         for(int i =1;i <= n;i ++)68         {69             scanf("%d",&a[i].num);70             a[i].s = i  ;71         }72         sort(a+1,a+1+n,cmp);73         int t = 1; 74         a[1].rs = 1; 75         for(int i = 2;i <= n;i ++)76         {77             if(a[i].num == a[i-1].num) 78                 a[i].rs = t ;79             else {80                 t++;81                 a[i].rs = t; 82             }83         }84         sort(a+1,a+1+n,cmp1);85         sum = 0 ;86         for(int i = 1;i <= n;i ++)87         {88             sum += (getsum(n)- getsum(a[i].rs));89             update(a[i].rs);90         }91         if(sum > k)92           cout << sum-k << endl;93         else printf("0\n");94     }95     return 0;96 }