【codeforces 131E】Yet Another Task with Queens

【题目链接】:http://codeforces.com/problemset/problem/131/E

【题意】

给你n*n坐标上的m个皇后的位置;
然后让你求出,能够攻击到0,1,2…8个其他皇后的皇后个数;
(其他皇后可以被前面的皇后挡住,所以最多只能攻击到8个);

【题解】

按照横、纵、正对角、斜对角这4个方向搞;
横坐标的话,将纵坐标升序排;
然后对于每一个横坐标,将横坐标为它的皇后的标号加入到vector里面;
(因为纵坐标升序排了,所以最两端的皇后就是vector里面第一个和最后一个皇后,那两个皇后能攻击到的个数+1,其他的+2);
纵坐标、对角同理;

【Number Of WA

1

【完整代码】

#include <bits/stdc++.h>
using namespace std;
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
#define LL long long
#define rep1(i,a,b) for (int i = a;i <= b;i++)
#define rep2(i,a,b) for (int i = a;i >= b;i--)
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define ms(x,y) memset(x,y,sizeof x)
#define Open() freopen("F:\rush.txt","r",stdin)
#define Close() ios::sync_with_stdio(0),cin.tie(0)

typedef pair<int,int> pii;
typedef pair<LL,LL> pll;

const int dx[9] = {0,1,-1,0,0,-1,-1,1,1};
const int dy[9] = {0,0,0,-1,1,-1,1,-1,1};
const double pi = acos(-1.0);
const int N = 1e5+100;

struct dian{
    int x,y,id;
};

dian a[N];
int n,m,can[N],ans[10];
vector <int> dic[N*3];

void init(){
    rep1(i,0,(int) 3e5) dic[i].clear();
}

int main(){
    //Open();
    Close();//scanf,puts,printf not use
    //init??????
    cin >> n >> m;
    rep1(i,1,m){
        cin >> a[i].x >> a[i].y;
        a[i].id = i;
    }

    sort(a+1,a+1+m,[&] (dian a,dian b){return a.y<b.y;});
    rep1(i,1,m){
        dic[a[i].x].pb(a[i].id);
    }
    rep1(i,1,n){
        if ((int) dic[i].size()>1){
            rep1(j,0,(int) dic[i].size()-1){
                if (j==0 || j == (int) dic[i].size()-1){
                    can[dic[i][j]]++;
                }
                else
                    can[dic[i][j]]+=2;
            }
        }
    }

    sort(a+1,a+1+m,[&] (dian a,dian b){return a.x<b.x;});
    init();
    rep1(i,1,m){
        dic[a[i].y].pb(a[i].id);
    }
    rep1(i,1,n){
        if ((int) dic[i].size()>1){
            rep1(j,0,(int) dic[i].size()-1){
                if (j==0 || j == (int) dic[i].size()-1){
                    can[dic[i][j]]++;
                }
                else
                    can[dic[i][j]]+=2;
            }
        }
    }

    init();
    rep1(i,1,m){
        dic[a[i].x+a[i].y].pb(a[i].id);
    }
    rep1(i,1,2*n){
        if ((int) dic[i].size()>1){
            rep1(j,0,(int) dic[i].size()-1){
                if (j==0 || j == (int) dic[i].size()-1){
                    can[dic[i][j]]++;
                }
                else
                    can[dic[i][j]]+=2;
            }
        }
    }

    init();
    rep1(i,1,m){
        dic[a[i].x-a[i].y+(int)1e5].pb(a[i].id);
    }
    rep1(i,0,(int)2e5+10){
        if ((int) dic[i].size()>1){
            rep1(j,0,(int) dic[i].size()-1){
                if (j==0 || j == (int) dic[i].size()-1){
                    can[dic[i][j]]++;
                }
                else
                    can[dic[i][j]]+=2;
            }
        }
    }

    rep1(i,1,m){
        ans[can[i]]++;
    }

    rep1(i,0,8){
        cout << ans[i]<<(i==8?'
':' ');
    }
    return 0;
}
原文地址:https://www.cnblogs.com/AWCXV/p/7626280.html