B. Vasya and Cornfield(线性规划)

    xiaoxiao2022-07-13  175

    Vasya owns a cornfield which can be defined with two integers nn and dd . The cornfield can be represented as rectangle with vertices having Cartesian coordinates (0,d),(d,0),(n,n−d)(0,d),(d,0),(n,n−d) and (n−d,n)(n−d,n) .

    An example of a cornfield with n=7n=7 and d=2d=2 .

    Vasya also knows that there are mm grasshoppers near the field (maybe even inside it). The ii -th grasshopper is at the point (xi,yi)(xi,yi) . Vasya does not like when grasshoppers eat his corn, so for each grasshopper he wants to know whether its position is inside the cornfield (including the border) or outside.

    Help Vasya! For each grasshopper determine if it is inside the field (including the border).

    Input

    The first line contains two integers nn and dd (1≤d<n≤1001≤d<n≤100 ).

    The second line contains a single integer mm (1≤m≤1001≤m≤100 ) — the number of grasshoppers.

    The ii -th of the next mm lines contains two integers xixi and yiyi (0≤xi,yi≤n0≤xi,yi≤n ) — position of the ii -th grasshopper.

    Output

    Print mm lines. The ii -th line should contain "YES" if the position of the ii -th grasshopper lies inside or on the border of the cornfield. Otherwise the ii -th line should contain "NO".

    You can print each letter in any case (upper or lower).

    Examples

    Input

    Copy

    7 2 4 2 4 4 1 6 3 4 5

    Output

    Copy

    YES NO NO YES

    Input

    Copy

    8 7 4 4 4 2 8 8 1 6 1

    Output

    Copy

    YES NO YES YES

    Note

    The cornfield from the first example is pictured above. Grasshoppers with indices 11 (coordinates (2,4)(2,4) ) and 44 (coordinates (4,5)(4,5) ) are inside the cornfield.

    The cornfield from the second example is pictured below. Grasshoppers with indices 11 (coordinates (4,4)(4,4) ), 33 (coordinates (8,1)(8,1) ) and 44 (coordinates (6,1)(6,1) ) are inside the cornfield.

     

       这不是高中线性规划的知识吗。果然所学的知识总有一天会用到的。

    #include<iostream> #include<iomanip> //#include<bits/stdc++.h> #include<cstdio> #include<cmath> #include<string> #include<algorithm> #include<cstring> #include<vector> #include<sstream> #include<queue> #include<set> #define PI 3.14159265358979 #define LL long long using namespace std; //const int MAX=1010; int main() { ios::sync_with_stdio(false); cin.tie(0); int n,m; cin>>n>>m; int k=n-m; int T; cin>>T; int x,y; for(int i=1;i<=T;++i) { cin>>x>>y; if(x+y<m||x-y>m||x+y>2*n-m||x+y<-m) cout<<"No"<<endl; else cout<<"Yes"<<endl; } }

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