Submission #133124

# Submission time Handle Problem Language Result Execution time Memory
133124 2019-07-20T07:46:41 Z sealnot123 Mobile (BOI12_mobile) C++14
0 / 100
308 ms 31492 KB
#include<bits/stdc++.h>
#define x first
#define y second
#define pb push_back
#define eb emplace_back
#define all(a) (a).begin(),(a).end()
#define SZ(a) (int)(a).size()
using namespace std;
typedef long long LL;
typedef pair<LL,LL> PLL;
typedef pair<int,int> PII;
typedef double D;
typedef long double LD;
const int N = 1000007;
PLL tower[N];
PLL intersect(PLL a, PLL b){
	LL A, B;
	A = a.y - b.y;
	B = b.x - a.x;
	if(B < 0) A = -A, B = -B;
	return {A, B};
}
vector<PLL> line;
void add(PLL nw){
	while(SZ(line)>1){
		int a = SZ(line);
		if(line[a-1].x == nw.x) return;
		PLL tmp1 = intersect(line[a-2], line[a-1]);
		PLL tmp2 = intersect(line[a-1], nw);
		if(tmp2.x*tmp1.y < tmp1.x*tmp2.y) line.pop_back();
		else break;
	}
	line.pb(nw);
}
LD calc(LD a, int b){
	return a*line[b].x + line[b].y;
}
LL L;
int n;

int main(){
	int i,j;
	LL a,b;
	scanf("%d %lld",&n,&L);
	for(i=1;i<=n;i++){
		scanf("%lld%lld",&a,&b);
		tower[i] = {-a*2ll, a*a + b*b};
	}
	sort(tower+1, tower+1+n);
    for(i=1;i<=n;i++){
    	add(tower[i]);
    }
    LD ans = 0;
    for(i = 0; i < SZ(line)-1; i++){
    	PLL tmp = intersect(line[i], line[i+1]);
    	LD tmp2 = (LD)tmp.x/tmp.y;
    	if(tmp2 < 0 || tmp2 > L) continue;
    	ans = max(ans, calc(tmp2, i) + tmp2*tmp2);
    }
    for(i=0; i<SZ(line)-1; i++){
    	if(calc(0, i) <= calc(0, i+1)) break;
    }
    ans = max(ans, calc(0, i));
    for(i=0; i<SZ(line)-1; i++){
    	if(calc(L, i) <= calc(L, i+1)) break;
    }
    ans = max(ans, calc(L, i) + L*L);
    printf("%Lf",sqrt(ans));
    return 0;
}
/*
2 10
0 0
11 1
*/

Compilation message

mobile.cpp: In function 'int main()':
mobile.cpp:42:8: warning: unused variable 'j' [-Wunused-variable]
  int i,j;
        ^
mobile.cpp:44:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %lld",&n,&L);
  ~~~~~^~~~~~~~~~~~~~~~~
mobile.cpp:46:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lld%lld",&a,&b);
   ~~~~~^~~~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 376 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 376 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 376 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 504 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 504 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 504 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 20 ms 2168 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 23 ms 2296 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 22 ms 2412 KB Output is correct
2 Incorrect 29 ms 3064 KB Output isn't correct
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 37 ms 2652 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 32 ms 2552 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 115 ms 8868 KB Output is correct
2 Incorrect 153 ms 15856 KB Output isn't correct
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 155 ms 8772 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 138 ms 10488 KB Output is correct
2 Incorrect 186 ms 19088 KB Output isn't correct
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 187 ms 10292 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 163 ms 11976 KB Output is correct
2 Incorrect 222 ms 22240 KB Output isn't correct
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 220 ms 11896 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 190 ms 13560 KB Output is correct
2 Incorrect 269 ms 25352 KB Output isn't correct
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 254 ms 13432 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 234 ms 16760 KB Output is correct
2 Incorrect 308 ms 31492 KB Output isn't correct
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 308 ms 16064 KB Output isn't correct
2 Halted 0 ms 0 KB -