Submission #90958

#	Time	Username	Problem	Language	Result	Execution time	Memory
90958		tincamatei	Circle selection (APIO18_circle_selection)	C++14	49 / 100	3042 ms	83212 KiB

circle_selection

#include <bits/stdc++.h>

using namespace std;

const int MAX_N = 300000;
int xc[1+MAX_N], yc[1+MAX_N], rc[1+MAX_N];
int poz[1+MAX_N], rez[1+MAX_N];
double ld[1+MAX_N], rd[1+MAX_N];
set<pair<double, int>> sl, sr;

bool cmp(int a, int b) {
	return rc[a] > rc[b] || (rc[a] == rc[b] && a < b);
}

double dist(int xa, int ya, int xb, int yb) {
	return sqrt((long long)(xa - xb) * (xa - xb) +
	            (long long)(ya - yb) * (ya - yb));
}

int main() {
#ifdef HOME
	FILE *fin = fopen("input.in", "r");
	FILE *fout = fopen("output.out", "w");
#else
	FILE *fin = stdin;
	FILE *fout = stdout;
#endif

	int n, ox, oy;

	srand(time(NULL));

	ox = rand() % 2000000001 - 1000000000;
	oy = rand() % 2000000001 - 1000000000;
	
	fscanf(fin, "%d", &n);
	for(int i = 1; i <= n; ++i) {
		fscanf(fin, "%d%d%d", &xc[i], &yc[i], &rc[i]);
		
		double d = dist(ox, oy, xc[i], yc[i]);

		ld[i] = d - rc[i];
		rd[i] = d + rc[i];
		
		sl.insert(make_pair(ld[i], i));
		sr.insert(make_pair(rd[i], i));
		poz[i - 1] = i;
	}

	sort(poz, poz + n, cmp);

	for(int i = 0; i < n; ++i) {
		int x = poz[i];
		
		if(rez[x] == 0) {
			set<pair<double, int> >::iterator it;

			it = sl.lower_bound(make_pair(ld[x], -1));
		
			while(it != sl.end() && it->first <= rd[x]) {
				int todel = it->second;
					
				if((long long)(rc[x] + rc[todel]) * (rc[x] + rc[todel]) >= 
				   (long long)(xc[x] - xc[todel]) * (xc[x] - xc[todel]) +
				   (long long)(yc[x] - yc[todel]) * (yc[x] - yc[todel])) {
					rez[todel] = x;
	
					sr.erase(make_pair(rd[todel], todel));
					it = sl.erase(it);
				} else
					it++;
			}
	
			it = sr.lower_bound(make_pair(ld[x], -1));
			while(it != sr.end() && it->first <= rd[x]) {
				int todel = it->second;
				if((long long)(rc[x] + rc[todel]) * (rc[x] + rc[todel]) >= 
				   (long long)(xc[x] - xc[todel]) * (xc[x] - xc[todel]) +
				   (long long)(yc[x] - yc[todel]) * (yc[x] - yc[todel])) {
					rez[todel] = x;
	
					sl.erase(make_pair(ld[todel], todel));
					it = sr.erase(it);
				} else
					it++;
			}
		}
	}
	
	for(int i = 1; i <= n; ++i)
		fprintf(fout, "%d ", rez[i]);

#ifdef HOME
	fclose(fin);
	fclose(fout);
#endif
	return 0;
}

Compilation message (stderr)

circle_selection.cpp: In function 'int main()':
circle_selection.cpp:36:8: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  fscanf(fin, "%d", &n);
  ~~~~~~^~~~~~~~~~~~~~~
circle_selection.cpp:38:9: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   fscanf(fin, "%d%d%d", &xc[i], &yc[i], &rc[i]);
   ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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