P2501 [HAOI2006] sequence number (LIS, DP) (unfinished)

The second hello fans. . .

#include "Head.cpp"
#include <vector>

const int N = 35007;

vector<int> V[N];
int a[N], b[N], f[N];
int sum1[N], sum2[N], dp[N];
int main(){
    int n;
    io >> n;
    R(i,1,n){
        io >> a[i];
        a[i] -= i;
    } 
    a[++n] = 0x3f3f3f3f;
    int len = 1;
    b[len] = a[1];
    f[1] = 1;
    R(i,2,n){
        if(a[i] >= b[len]){
            b[++len] = a[i];
            f[i] = len;
        }
        else{
            int pos = upper_bound(b + 1, b + len + 1, a[i]) - b;
            b[pos] = a[i];
            f[i] = pos;
        }
    }
    
    printf("%d\n", n - f[n]);
    
    a[0] = -0x3f3f3f3f;
    V[0].push_back(0);
    R(i,1,n){
        dp[i] = 0x3f3f3f3f;
        for(vector<int>::iterator j = V[f[i] - 1].begin(); j != V[f[i] - 1].end(); ++j){
            if(a[*j] > a[i]) continue;
            sum1[*j - 1] = sum2[*j - 1] = 0;
            R(k,*j,i){
                sum1[k] = sum1[k - 1] + Abs(a[i] - a[k]);
                sum2[k] = sum2[k - 1] + Abs(a[*j] - a[k]);
            }
            R(k,*j,i){
                dp[i] = Min(dp[i], dp[*j] - sum2[*j] - sum1[k] + sum2[k] + sum1[i]);
            }
        }
        V[f[i]].push_back(i);
    }
    
    printf("%d\n", dp[n]);
        
    return 0;
}