洛谷P1281 书的复制

洛谷P1281 书的复制
二分

 

 1 #include <bits/stdc++.h> 
 2 #define For(i,j,k) for(int i=j;i<=k;i++) 
 3 using namespace std ; 
 4 
 5 const int N = 511,M = 511 ; 
 6 int a[N],L[M],R[M] ; 
 7 int n,k,MAX,num ; 
 8 struct node{
 9     int l,r ; 
10 }ans[N] ;
11 
12 inline int read() 
13 {
14     int x = 0 , f = 1 ; 
15     char ch = getchar() ; 
16     while(ch<'0'||ch>'9') { if(ch=='-') f = -1 ; ch = getchar() ; } 
17     while(ch>='0'&&ch<='9') { x = x * 10+ch-48 ; ch = getchar() ; } 
18     return x * f ;  
19 }
20 
21 inline bool check(int mid) 
22 {
23     int sum = 0 ; 
24     num = 0 ; 
25     ans[++num].l = 1 ; 
26     For(i,1,n) {
27         if(sum+a[i] > mid) 
28             ans[num].r = i-1 ,ans[++num].l = i,sum = 0 ; 
29         sum+=a[i] ;  
30     }
31     ans[num].r = n ; 
32     return num <= k ; 
33 }
34 
35 inline void work() 
36 {
37     int l = 0,r = MAX ; 
38     while(l<r) {
39         int mid = (l+r)>>1 ; 
40         if(check(mid)) 
41             r = mid ; 
42         else 
43             l = mid + 1 ; 
44     }
45     check(r) ; 
46     for(int i=k;i>=1;i--) 
47         printf("%d %d\n",n-ans[i].r+1,n-ans[i].l+1) ; 
48 }
49 
50 int main() 
51 {
52     n = read() ; k = read() ; 
53     For(i,1,n) a[i] = read(),MAX+=a[i] ; 
54     For(i,1,n/2) swap(a[i],a[n-i+1]) ; 
55     work() ; 
56     return 0 ; 
57 }

 

posted @ 2017-09-16 15:50  third2333  阅读(170)  评论(0)  编辑  收藏  举报