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Submission #829746

# Submission time Handle Problem Language Result Execution time Memory
829746 2023-08-18T14:45:21 Z soumyojit_sen Mobile (BOI12_mobile) C++14
12 / 100
 675 ms 23676 KB 
#include <bits/stdc++.h>
using namespace std;
vector<pair<int,int>> pts;
int n;
double L;

bool works(double d){
	// whether a radius of d is enough to intersect all the circles
	double currDistCovered = 0.0;
	for(int i = 0; i < n; i++){
		// find the segment covered by ith circle on the highway
		// radius^2 = yi^2 + dist^2
		double dist = sqrt(d*d - pts[i].second*pts[i].second);
		double start = pts[i].first - dist;
		double end = pts[i].first + dist;

		if(start <= currDistCovered){
			currDistCovered = max(currDistCovered, end);
		}
	}
	return currDistCovered >= L;

}

int main() {
	cin >> n >> L;
	pts.resize(n);
	for(int i = 0; i < n; i++) cin >> pts[i].first >> pts[i].second;

	double good = 5e9;
	double bad = -1.0;
	
	for(int i = 0; i < 60; i++){
		double mid = bad + (good - bad)/2;
		if(works(mid)){
			good = mid;
		} else {
			bad = mid;
		}
	}
	cout << fixed << setprecision(6) << good;
}

Subtask #1
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 300 KB Output is correct

Subtask #2
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct

Subtask #3
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 340 KB Output is correct
2 Correct 2 ms 308 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 2 ms 340 KB Output is correct

Subtask #4
0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 316 KB Output is correct
2 Correct 3 ms 340 KB Output is correct
3 Correct 3 ms 372 KB Output is correct
4 Incorrect 4 ms 340 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #5
0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 388 KB Output is correct
2 Correct 4 ms 340 KB Output is correct
3 Correct 3 ms 340 KB Output is correct
4 Incorrect 4 ms 340 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #6
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 388 KB Output is correct
2 Correct 3 ms 340 KB Output is correct
3 Correct 3 ms 340 KB Output is correct
4 Incorrect 4 ms 340 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #7
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 54 ms 1640 KB Output is correct
2 Incorrect 46 ms 1896 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #8
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 44 ms 1644 KB Output is correct
2 Correct 44 ms 1596 KB Output is correct
3 Incorrect 66 ms 1952 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #9
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 51 ms 1620 KB Output is correct
2 Incorrect 49 ms 2088 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #10
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 78 ms 2508 KB Output is correct
2 Incorrect 59 ms 2464 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #11
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 65 ms 2596 KB Output is correct
2 Incorrect 64 ms 2464 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #12
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 241 ms 8492 KB Output is correct
2 Incorrect 326 ms 11932 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #13
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 360 ms 11884 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #14
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 292 ms 10152 KB Output is correct
2 Incorrect 439 ms 14272 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #15
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 439 ms 12664 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #16
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 338 ms 11816 KB Output is correct
2 Incorrect 485 ms 16636 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #17
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 575 ms 13328 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #18
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 416 ms 13480 KB Output is correct
2 Incorrect 527 ms 18972 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #19
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 591 ms 13984 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #20
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 520 ms 15800 KB Output is correct
2 Incorrect 672 ms 23676 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #21
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 675 ms 12108 KB Output isn't correct
2 Halted 0 ms 0 KB -