[NOI1999] 01 skewers

Title Description

Given 7 integer N,A0,B0,L0,A1,B1,L1, it is required to design a 01-string s=s1s2...si...sn that satisfies:
1.si=0 or si=1,1<=i<=n;
2. For any contiguous length of S L0 sjsj+1...sj+l0-1 (1<=j<=n-l0+1), the number of 0 is greater than or equal to A0 and less than or equal to B0;
3. For any contiguous length of S L1 sjsj+1...sj+l1-1 (1<=j<=n-l1+1), the number of 1 is greater than or equal to A1 and less than or equal to B1;
For example, n=6,a0=1,b0=2,l0=3,a1=1,b1=1,l1=2, there is a 01-string s=010101 that satisfies all of the above conditions. Input Format

Only one row, with 7 integers, which in turn represents N,A0,B0,L0,A1,B1,L1 (3<=n<=1000,1<= a0<=b0<=l0<=n,1<=a1<=b1<=l1<=n), The adjacent two integers are separated by a space. output Format

Only one row, if there are no 01 strings that satisfy all the conditions, output an integer-1, otherwise the output satisfies the maximum of 1 of the 01 strings in all conditions. Sample Data Sample Input

6 1 2 3 1 1 2 sample output

3 Description

01 strings satisfying the conditions for 010101 problem Analysis

This problem should be special judge, and many OJ on the market are not added.
Set the binary string to T[1...N]
Set S[i] to the number of ' 1 ' in the first I character of T
Apparently, the latter one is only 1 bigger than the previous one.
Have
Si−si−1≤1 S_i-s_{i-1}\le 1
Si−1−si≤0 S_{i-1}-s_i\le 0
By the question, the number of 0 is greater than or equal to A0 and less than or equal to B0
The number of conversions to 1 is greater than or equal to l0-b0, less than or equal to l0-a0
So there are
Si−1−si+l0−1≤b0−l0 S_{i-1}-s_{i+l_0-1}\le B_0-l_0
SI+L0−1−SI−1≤L0−A0 S_{i+l_0-1}-s_{i-1}\le L_0-a_0
SI−1−SI+L1−1≤−A1 s_{i-1}-s_{i+l_1-1}\le-a_1
SI+L1−1−SI−1≤B1 S_{i+l_1-1}-s_{i-1}\le b_1
Because all is less than the character, differential constraints run the shortest possible time to find out s[i]
Then construct 01 sequence according to S[i]

Source Code

No special judge OJ please don't write according to my Code

#include <algorithm> #include <iostream> #include <iomanip> #include <cstring> #include < cstdlib> #include <vector> #include <cstdio> #include <cmath> #include <queue> using
namespace Std;
    inline const int Get_int () {int num=0,bj=1;
    Char X=getchar (); while (x< ' 0 ' | |
        X> ' 9 ') {if (x== '-') bj=-1;
    X=getchar ();
        } while (x>= ' 0 ' &&x<= ' 9 ') {num=num*10+x-' 0 ';
    X=getchar ();
} return NUM*BJ;
} const int maxn=2005;
struct Edge {int from,to,dist;};
    struct Difference_constraints {//differential constrained system int n,m;
    vector<edge>edges;
    vector<int>g[maxn];
    BOOL INQUE[MAXN];
    int DIST[MAXN],USED[MAXN];
        void init (int n) {this->n=n;
        Edges.clear ();
    for (int i=1; i<=n; i++) g[i].clear ();
        } void Addedge (int from,int to,int dist) {edges.push_back ((Edge) {from,to,dist});
       M=edges.size (); G[from].push_back (m-1);
    } void Insert (int x,int Y,int v) {//x-y<=v (flag=0), X-y>=v (flag=1) Addedge (Y,X,V);
        } bool SPFA (int s) {for (int i=1; i<=n; i++) Dist[i]=0x7fffffff/2;
        memset (inque,0,sizeof (Inque));
        deque<int>q;
        Q.push_back (s);
        dist[s]=0; inque[s]=