Submission #300049

#	Time	Username	Problem	Language	Result	Execution time	Memory
300049		MarcoMeijer	Aliens (IOI16_aliens)	C++14	60 / 100	2085 ms	6764 KiB

aliens

#include "aliens.h"
#include <bits/stdc++.h>

using namespace std;

#define REP(a,b,c) for(int a=int(b); a<int(c); a++)
#define REV(a,b,c) for(int a=int(c-1); a>=int(b); a--)
#define RE(a,b) REP(a,0,b)
#define FOR(a,b) for(auto& a:b)
#define pb push_back
#define fi first
#define se second
#define all(a) a.begin(), a.end()

typedef long long ll;
typedef pair<int,int> ii;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;

const int INF=1e9;
const int MX=2e5;

vi r, c, le, ri;
int n, m, k;
int SA[MX];

vll dp, odp;

ll getCost(int i, int j) {
    ll w = ri[j]-le[i]+1;
    ll res = w*w;
    if(j != n-1) {
        ll sw = ri[j]-le[j+1]+1;
        if(sw > 0)
            res -= sw*sw;
    }
    return res;
}
void computeDP(int l, int r, int optl, int optr) {
    if(r < l) return;
    int m = (l+r)/2;

    int opt = -1;
    dp[m] = 1e18;
    REP(j,optl,min(optr+1,m)) {
        ll ndp = odp[j] + getCost(j,m-1);
        if(ndp < dp[m]) {
            dp[m] = ndp;
            opt = j;
        }
    }

    computeDP(l, m-1, optl, opt);
    computeDP(m+1, r, opt, optr);
}

ll take_photos(int _n, int _m, int _k, vi _r, vi _c) {
    n=_n; m=_m; k=_k; r=_r; c=_c;
    RE(i,n) if(c[i] < r[i]) swap(c[i], r[i]);
    RE(i,n) SA[i] = i;
    sort(SA,SA+n,[](int i, int j) {
        if(r[i] == r[j]) return c[i] > c[j];
        return r[i] < r[j];
    });
    ll mxr = -1;
    RE(i,n) {
        if(c[SA[i]] <= mxr) continue;
        le.pb(r[SA[i]]);
        ri.pb(c[SA[i]]);
        mxr = c[SA[i]];
    }
    n = le.size();

    if(k > n) k = n;
    dp.assign(n+1,1e18); dp[0] = 0;
    REP(i,1,k+1) {
        odp = dp;
        computeDP(1,n,0,n-1);
    }
    return dp[n];
}

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