Submission #522518

#	Time	Username	Problem	Language	Result	Execution time	Memory
522518		byunjaewoo	Aliens (IOI16_aliens)	C++17	Compilation error	0 ms	0 KiB

aliens

#include <bits/stdc++.h>
#define x first
#define y second
using namespace std;
using ll=long long;
using ld=long double;
using pp=pair<ll, ll>;
      
const int Nmax=100010;
ll N, NN, M, K, DP[Nmax], C[Nmax];
pp A[Nmax], B[Nmax];
struct line {
    ll a, b;
    int idx;
    ll f(ll x) {return a*x+b;}
    ld cross(line r) {return (b-r.b)/(r.a-a);}
}L[Nmax];
      
void Dynamic(ll v) {
    int fr=1, re=0;
    for(int i=1; i<=N; i++) {
        line tmp={-2*A[i].x, DP[i-1]+A[i].x*A[i].x-2*A[i].x, i};
        if(i<N && A[i+1].x<=A[i].y) tmp.b-=(A[i].y-A[i+1].x+1)*(A[i].y-A[i+1].x+1);
        while(fr<re && L[re-1].cross(tmp)<=L[re-1].cross(L[re])) re--;
        L[++re]=tmp;
        while(fr<re && L[fr].f(A[i].y)>=L[fr+1].f(A[i].y)) fr++;
        DP[i]=L[fr].f(A[i].y)+A[i].y*A[i].y+v+2*A[i].y+1;
        if(L[fr].idx==0) C[i]=1;
        else C[i]=C[L[fr].idx-1]+1;
    }
}
      
int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin>>NN>>M>>K;
    for(int i=1; i<=NN; i++) {
        int r, c; cin>>r>>c;
        B[i].x=min(r, c), B[i].y=max(r, c);
    }
    sort(B+1, B+NN+1, [](pp a, pp b) {return a.x!=b.x?a.x<b.x:a.y>b.y;});
    for(int i=1; i<=NN; i++) {
        if(N && B[i].y<=A[N].y) continue;
        while(N && A[N].y>=B[i].y) N--;
        A[++N]=B[i];
    }
    K=min(K, N);
    ll l=0, r=N+1, lv, rv;
    for(ll s=0, e=M*M; s<=e;) {
        ll mid=(s+e)/2;
        Dynamic(mid);
        if(C[N]==K) {
            cout<<DP[N]-mid*C[N];
            return 0;
        }
        else if(C[N]>K) {
            s=mid+1;
            if(r>C[N]) r=C[N], rv=DP[N]-mid*C[N];
        }
        else {
            e=mid-1;
            if(l<C[N]) l=C[N], lv=DP[N]-mid*C[N];
        }
    }
    cout<<rv+(lv-rv)/(r-l)*(r-K);
    return 0;
}

Compilation message (stderr)

aliens.cpp: In function 'int main()':
aliens.cpp:64:32: warning: 'rv' may be used uninitialized in this function [-Wmaybe-uninitialized]
   64 |     cout<<rv+(lv-rv)/(r-l)*(r-K);
      |                                ^
aliens.cpp:64:17: warning: 'lv' may be used uninitialized in this function [-Wmaybe-uninitialized]
   64 |     cout<<rv+(lv-rv)/(r-l)*(r-K);
      |              ~~~^~~~
/usr/bin/ld: /tmp/ccaQcSkj.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/cc67Mi1f.o:aliens.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/ccaQcSkj.o: in function `main':
grader.cpp:(.text.startup+0xf0): undefined reference to `take_photos(int, int, int, std::vector<int, std::allocator<int> >, std::vector<int, std::allocator<int> >)'
collect2: error: ld returned 1 exit status