BZOJ 3229: [Sdoi2008]石子合并

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstdlib>
 4 #include<cmath>
 5 #include<algorithm>
 6 #define yyj(s) freopen(s".in","r",stdin),freopen(s".out","w",stdout);
 7 #define llg long long
 8 #define maxn 40010
 9 llg i,j,k,x,n,m,a[maxn],ans;
10 using namespace std;
11 llg get()
12 {
13     llg i=0; char c=getchar();
14     while(c>‘9‘||c<‘0‘)c=getchar();
15     while(c>=‘0‘&&c<=‘9‘)i=i*10+c-‘0‘,c=getchar();
16     return i;
17 }
18 
19 int main()
20 {
21     yyj("a");
22     cin>>n;
23     for (i=1;i<=n;i++) a[i]=get(); 
24     a[0]=a[n+1]=0x7fffffff;
25     for (m=1;m<n;m++)
26         {
27             a[n-m+2]=0x7fffffff;
28             for (k=2;k<=n-m+1;k++) if (a[k-1]<=a[k+1]) break;
29             x=a[k-1]+a[k]; ans+=x;
30             for (i=k-1;i<=n-m;i++) a[i]=a[i+2];
31             for (j=k-2;j>=0;j--) if (a[j]>x) break;
32             for (i=n-m;i>j+1;i--) a[i]=a[i-1];
33             a[j+1]=x;
34         }
35     cout<<ans;
36     return 0;
37 }