Submission #390702

#	Time	Username	Problem	Language	Result	Execution time	Memory
390702		ponytail	Aliens (IOI16_aliens)	C++17	12 / 100	37 ms	2256 KiB

aliens

#include "bits/stdc++.h"
#define int long long
#define fi first
#define se second
#define pb push_back
using namespace std;
const int BIG = 1e18;
const int is_query = -BIG;
struct line {
    int m, b;
    mutable function<const line*()> succ;
    bool operator<(const line& rhs) const {
        if (rhs.b != is_query) return m < rhs.m;
        const line* s = succ();
        if (!s) return 0;
        int x = rhs.m;
        return b - s->b < (s->m - m) * x;
    }
};
struct dynamic_hull : public multiset<line> {
   const int inf = BIG;
   bool bad(iterator y) {
       auto z = next(y);
       if (y == begin()) {
           if (z == end()) return 0;
           return y->m == z->m && y->b <= z->b;
       }
       auto x = prev(y);
       if (z == end()) return y->m == x->m && y->b <= x->b;
       int v1 = (x->b - y->b);
       if (y->m == x->m) v1 = x->b > y->b ? inf : -inf;
       else v1 /= (y->m - x->m);
       int v2 = (y->b - z->b);
       if (z->m == y->m) v2 = y->b > z->b ? inf : -inf;
       else v2 /= (z->m - y->m);
       return v1 >= v2;
   }
   void insert_line(int m, int b) {
       auto y = insert({m,b});
       y->succ = [=] { return next(y) == end() ? 0 : &*next(y); };
       if (bad(y)) { erase(y); return; }
       while (next(y) != end() && bad(next(y))) erase(next(y));
       while (y != begin() && bad(prev(y))) erase(prev(y));
   }
   int eval(int x) {
       auto l = *lower_bound((line) { x, is_query });
       return l.m * x + l.b;
   }
};
int N,M,K;
int take_photos(signed N, signed M,signed K,vector<signed>r, vector<signed>c){
    map<pair<int,int>,int>iexist;
    int MAX[M];
    for(int i=0;i<M;i++) MAX[i]=-1;
    for(int i=0;i<N;i++){
        if(r[i]>c[i]){
            swap(r[i],c[i]);
        }
        iexist[{r[i],c[i]}]=1;
        MAX[r[i]]=max(MAX[r[i]],(int)c[i]);
    }
    int prefMAX[M];
    prefMAX[0]=MAX[0];
    for(int i=1;i<M;i++){
        prefMAX[i]=max(prefMAX[i-1], MAX[i]);
    }
    map<pair<int,int>,int>idontexist;
    for(pair<pair<int,int>,int> x:iexist){
        if(x.fi.fi>0 && prefMAX[x.fi.fi-1]>=x.fi.se) continue;
        if(MAX[x.fi.fi]>x.fi.se) continue;
        idontexist[x.fi]=1;
    }
    iexist.clear();
    for(pair<pair<int,int>,int> x:idontexist){
        iexist[x.fi]=1;
    }
    N=iexist.size();
    int pointer=0;
    for(pair<pair<int,int>,int> x:iexist){
        r[pointer]=x.fi.fi;
        c[pointer]=x.fi.se;
        pointer++;
    }
    K=min(K,N);
    int dp[K+1][N];
    for(int i=0;i<N;i++){
        dp[1][i]=(c[i]-r[0]+1)*(c[i]-r[0]+1);
    }
    for(int i=2;i<=K;i++){
        for(int j=i-1;j<N;j++){
            dp[i][j]=1e14;
            for(int k=i-2;k<j;k++){
                dp[i][j]=min(dp[i][j],dp[i-1][k]+(c[j]-r[k+1]+1)*(c[j]-r[k+1]+1));
            }
        }
    }
    int ans=1e18;
    for(int i=1;i<=K;i++) ans=min(ans, dp[i][N-1]);
    return ans;
}

• Subtask 1: 0 / 4
• Subtask 2: 12 / 12
• Subtask 3: 0 / 9
• Subtask 4: 0 / 16
• Subtask 5: 0 / 19
• Subtask 6: 0 / 40