数据备份

 1 #include <algorithm>
 2 #include <iostream>
 3 #include <cstdlib>
 4 #include <cstring>
 5 #include <string>
 6 #include <cstdio>
 7 #include <queue>
 8 using namespace std ;
 9 
10 int n , k ;
11 int sum[100006] , ans ;
12 bool used[100006] ;
13 struct node{
14     int  id , val;
15     bool operator < ( const node & a ) const {
16         return a.val < val ;
17     }
18 };
19 priority_queue < node > Q ;
20 int las[100006] ,nxt[100006] ;
21 
22 inline void Init (   ) {
23     freopen( "10344.in" , "r" , stdin ) ;
24     freopen( "10344.out" , "w" , stdout ) ;
25 }
26 
27 void input (   ) {
28     scanf( "%d%d" , &n , &k ) ;
29     int a ; scanf( "%d" ,&a ) ;
30     int b ;
31     for ( int x = 2 ; x <= n ; x++ ) {
32         scanf( "%d" , &b ) ;
33         node tep ;
34         sum[ x ] = b - a ;
35         las[x] = x - 1 , nxt[x] = x + 1 ;
36 //        tep.val = sum[x] , tep.id = x ; 
37         Q.push( node{ x , b - a } ) ;
38         a = b ;
39     }    
40 }
41 
42 
43 void sov(  ) {
44     int tot = 0  ;
45     sum[1] = sum[n+1] = (1<<30)-1;
46     while( tot < k  ) {
47         tot++ ;
48         node tep ;
49         while ( used[ Q.top( ).id ] ) Q.pop(  ) ;
50         tep = Q.top( ) ; Q.pop( ) ;
51         ans += tep.val ;
52         int  l = las[ tep.id ]  , r = nxt[ tep.id ]  , v = sum[ l ] + sum[ r ] - sum[ tep.id ];
53         sum[ tep.id ] = v ;
54         Q.push( node { tep.id , v } ) ;
55         if( l > 1 ) las[ tep.id ] = las[ l ] , nxt[ las[l] ] = tep.id , used[ l ] = true ;
56         if( r <= n )nxt[ tep.id ] = nxt[ r ] , las[ nxt[r] ] = tep.id , used[ r ] = true ;
57     }
58 }
59     
60     
61 void output(  ) {
62     printf( "%d\n" , ans ) ;
63 }
64     
65 
66 int main (  ) {
67 //    Init(  ) ;
68     input(  ) ;
69     sov(  ) ;
70     output(  ) ;
71 //    fclose(stdin);
72 //    fclose(stdout);
73     return 0 ;
74 }