제출 #522311

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
522311		byunjaewoo	Aliens (IOI16_aliens)	C++17	컴파일 에러	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=0, re=0;
    fill(C+1, C+N+1, 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};
        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;
        C[i]=C[L[fr].idx-1]+1;
    }
}

ll take_photos(int n, int m, int k, std::vector<int> r, std::vector<int> c) {
    NN=n, M=m, K=k;
    for(int i=1; i<=NN; i++) {
        B[i].x=min(r[i-1], c[i-1]), B[i].y=max(r[i-1], c[i-1]);
    }
    sort(B+1, B+NN+1);
    for(int i=NN; i>=1; i--) {
        while(N && A[N].y<=B[i].y) N--;
        A[++N]=B[i];
    }
    reverse(A+1, A+N+1); 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) {
            return DP[N]-mid*C[N];
        }
        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];
        }
    }
    return rv+(lv-rv)/(r-l)*(r-K);
}

컴파일 시 표준 에러 (stderr) 메시지

aliens.cpp: In function 'll take_photos(int, int, int, std::vector<int>, std::vector<int>)':
aliens.cpp:43:13: error: declaration of 'll r' shadows a parameter
   43 |     ll l=0, r=N+1, lv, rv;
      |             ^
aliens.cpp:32:54: note: 'std::vector<int> r' previously declared here
   32 | ll take_photos(int n, int m, int k, std::vector<int> r, std::vector<int> c) {
      |                                     ~~~~~~~~~~~~~~~~~^