BZOJ1233: [Usaco2009Open]干草堆tower

 1 #include<cstdio>
 2 #include<cstdlib>
 3 #include<cmath>
 4 #include<cstring>
 5 #include<algorithm>
 6 #include<iostream>
 7 #include<vector>
 8 #include<map>
 9 #include<set>
10 #include<queue>
11 #include<string>
12 #define inf 1000000000
13 #define maxn 101000
14 #define maxm 500+100
15 #define eps 1e-10
16 #define ll long long
17 #define pa pair<int,int>
18 #define for0(i,n) for(int i=0;i<=(n);i++)
19 #define for1(i,n) for(int i=1;i<=(n);i++)
20 #define for2(i,x,y) for(int i=(x);i<=(y);i++)
21 #define for3(i,x,y) for(int i=(x);i>=(y);i--)
22 #define mod 1000000007
23 using namespace std;
24 inline int read()
25 {
26     int x=0,f=1;char ch=getchar();
27     while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1;ch=getchar();}
28     while(ch>=‘0‘&&ch<=‘9‘){x=10*x+ch-‘0‘;ch=getchar();}
29     return x*f;
30 }
31 int n,s[maxn],q[maxn],wide[maxn],h[maxn];
32 int main()
33 {
34     freopen("input.txt","r",stdin);
35     freopen("output.txt","w",stdout);
36     n=read();
37     for1(i,n)s[i]=s[i-1]+read();
38     int l=0,r=0;q[0]=n+1;
39     for3(i,n,1)
40     {
41         while(l<r&&wide[q[l+1]]<=s[q[l+1]-1]-s[i-1])l++;
42         wide[i]=s[q[l]-1]-s[i-1];
43         h[i]=h[q[l]]+1;
44         while(l<r&&wide[i]-s[i-1]<wide[q[r]]-s[q[r]-1])r--;
45         q[++r]=i;
46     }
47     printf("%d\n",h[1]);
48     return 0;
49 }

 1 #include<iostream>
 2 #include<cstdio>
 3 using namespace std;
 4 int a[100010],d[100010],s[100010],f[100010],q[100010],n,i,j,l,r;
 5 int main()
 6 {
 7     cin>>n;
 8     for(i=n;i;i--) scanf("%d",&a[i]);
 9     for(i=1;i<=n;i++) s[i]=s[i-1]+a[i];
10     l=1;
11     for(i=1,j=0;i<=n;i++)
12     {
13         while(l<=r&&s[i]-s[q[l]]>=f[q[l]]) j=q[l++];
14         f[i]=s[i]-s[j];
15         d[i]=d[j]+1;
16         while(l<=r&&f[i]<=f[q[r]]-s[i]+s[q[r]]) r--;
17         q[++r]=i;
18     }
19     cout<<d[n]<<endl;
20     return 0;
21 }