Submission #50004

#	Time	Username	Problem	Language	Result	Execution time	Memory
50004		top34051	Circle selection (APIO18_circle_selection)	C++17	23 / 100	1762 ms	67184 KiB

circle_selection

//subtask 4
#include<bits/stdc++.h>
using namespace std;
#define ll long long
const int maxn = 3e5 + 5;
struct node {
    int x,y,r;
};
int n;
node p[maxn];
int R;
int res[maxn];
unordered_map<int,unordered_map<int,vector<int>>> mp;
bool cut(node a, node b) {
    return (ll)(a.x-b.x)*(a.x-b.x) + (ll)(a.y-b.y)*(a.y-b.y) <= (ll)(a.r+b.r)*(a.r+b.r);
}
int main() {
    scanf("%d",&n);
    for(int i=1;i<=n;i++) scanf("%d%d%d",&p[i].x,&p[i].y,&p[i].r);
    R = p[1].r;
    for(int i=1;i<=n;i++) {
        int x = p[i].x/R, y = p[i].y/R;
        res[i] = i;
        for(int xx=x-2;xx<=x+2;xx++) {
            for(int yy=y-2;yy<=y+2;yy++) {
                if(mp.count(xx)==0) continue;
                if(mp[xx].count(yy)==0) continue;
                for(auto t : mp[xx][yy]) {
                    if(cut(p[i], p[t])) {
                        res[i] = min(res[i], t);
                    }
                }
            }
        }
        if(res[i]==i) {
            mp[x][y].push_back(i);
        }
    }
    for(int i=1;i<=n;i++) printf("%d ",res[i]);
}

Compilation message (stderr)

circle_selection.cpp: In function 'int main()':
circle_selection.cpp:18:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&n);
     ~~~~~^~~~~~~~~
circle_selection.cpp:19:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for(int i=1;i<=n;i++) scanf("%d%d%d",&p[i].x,&p[i].y,&p[i].r);
                           ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 7
• Subtask 2: 0 / 12
• Subtask 3: 0 / 15
• Subtask 4: 23 / 23
• Subtask 5: 0 / 30
• Subtask 6: 0 / 13