Submission #687129

#	Time	Username	Problem	Language	Result	Execution time	Memory
687129		nikhil_kumart21	Mobile (BOI12_mobile)	C++17	0 / 100	1097 ms	131072 KiB

mobile

#include <bits/stdc++.h>

using namespace std;

typedef long double  ll;
#define endl "\n";

void setIO(string s) {
	freopen((s + ".in").c_str(), "r", stdin);
	freopen((s + ".out").c_str(), "w", stdout);
}
ll fun(vector<vector<ll>>&v,ll mid,ll L){
    vector<vector<ll>>a;
    // cout<<mid<<endl;
    for(auto it:v){
        if(mid<it[1])continue;
        ll l=it[0]-sqrtl(mid*mid-it[1]*it[1]),r=it[0]+sqrt(mid*mid-it[1]*it[1]);
        if(l<=L&&r>=0)
        a.push_back({l,r});

        // cout<<l<<" "<<r<<endl;
    }
    if(a.empty())return 1;
    // cout<<endl;
    // if()
    if(a[0][0]>0)return 1;
    ll num=a[0][1];
    for(int i=1;i<a.size();++i){
        auto it=a[i];
        if(it[0]>num)return 1;
        num=max(num,it[1]);
    }
    if(num<L)return 1;
    return 0;
}
    
int main()
{
    // setIO("angry");
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);cout.tie(NULL);
    
    ll n,L;
    cin>>n>>L;
    vector<vector<ll>>v;
    for(int i=0;i<n;++i){
        ll l,r;
        cin>>l>>r;
        v.push_back({l,r});
    }
    ll l=0,r=2e9,mid,ans=0;
    while(l<=r){
        mid=l+(r-l)/2;
        if(fun(v,mid,L)){
            l=mid+1e-5;
            ans=mid;
        }
        else{
            r=mid-1e-5;
        }
    }
    cout<<fixed<<setprecision(3)<<ans<<endl;
    
}

Compilation message (stderr)

mobile.cpp: In function 'll fun(std::vector<std::vector<long double> >&, ll, ll)':
mobile.cpp:30:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<long double> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |     for(int i=1;i<a.size();++i){
      |                 ~^~~~~~~~~
mobile.cpp: In function 'void setIO(std::string)':
mobile.cpp:11:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 |  freopen((s + ".in").c_str(), "r", stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mobile.cpp:12:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 |  freopen((s + ".out").c_str(), "w", stdout);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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