Submission #659086

#	Time	Username	Problem	Language	Result	Execution time	Memory
659086		eltu0815	Salesman (IOI09_salesman)	C++14	62 / 100	1100 ms	27296 KiB

salesman

#include <bits/stdc++.h>
#define MAX 500005
#define MOD (ll)(1e9+7)
#define INF 2100000000

using namespace std;
//typedef long long ll;
typedef complex<double> cpx;

int N, M, Q, U, D, S;
int dp[MAX][2];
int seg[4 * MAX][2];

struct Market {
    int t, l, c;
    bool operator < (Market& m) {
        if(t != m.t) return t < m.t;
        return l < m.l;
    }
} arr[MAX];

void init(int str, int ed, int node) {
    if(str == ed) {
        seg[node][0] = seg[node][1] = -INF;
        return;
    }
    
    int mid = str + ed >> 1;
    init(str, mid, node << 1); init(mid + 1, ed, node << 1 | 1);
    seg[node][0] = seg[node][1] = -INF;
}

void update(int str, int ed, int idx, int type, int node) {
    if(str == ed) {
        seg[node][0] = max(seg[node][0], dp[idx][type] + D * idx);
        seg[node][1] = max(seg[node][1], dp[idx][type] - U * idx);
        return;
    }
    
    int mid = str + ed >> 1;
    if(idx <= mid) update(str, mid, idx, type, node << 1);
    else update(mid + 1, ed, idx, type, node << 1 | 1);
    seg[node][0] = max(seg[node << 1][0], seg[node << 1 | 1][0]);
    seg[node][1] = max(seg[node << 1][1], seg[node << 1 | 1][1]);
}

int query(int str, int ed, int left, int right, int type, int node) {
    if(str > right || ed < left) return -INF;
    if(left <= str && ed <= right) return seg[node][type];
    
    int mid = str + ed >> 1;
    return max(query(str, mid, left, right, type, node << 1), query(mid + 1, ed, left, right, type, node << 1 | 1));
}

void solve(int type) {
    dp[S][type] = 0;
    init(1, M, 1);
    update(1, M, S, type, 1);
    
    int prv = 1;
    for(int i = 1; i <= N; ++i) {
        int j = arr[i].l;
        dp[j][type] = max(dp[j][type], arr[i].c - D * arr[i].l + query(1, M, 1, arr[i].l, 0, 1));
        dp[j][type] = max(dp[j][type], arr[i].c + U * arr[i].l + query(1, M, arr[i].l, M, 1, 1));
        update(1, M, arr[i].l, type, 1);
        
        if(i == N || arr[i + 1].t == arr[i].t) continue;
        for(int k = prv; k <= i; ++k) {
            //dp[arr[k].l][type] = max(dp[arr[k].l][type], dp[arr[k].l][type]);
            update(1, M, arr[k].l, !type, 1);
        }
        prv = i + 1;
    }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    
    cin >> N >> U >> D >> S; M = S;
    for(int i = 1; i <= N; ++i) {
        cin >> arr[i].t >> arr[i].l >> arr[i].c;
        M = max(M, arr[i].l); 
    }
    arr[0] = {-1, S, 0}; arr[++N] = {INF, S, 0};
    
    for(int i = 0; i <= M; ++i) dp[i][0] = dp[i][1] = -INF;
    sort(arr, arr + N); solve(0);
    sort(arr, arr + N, [&](auto a, auto b) {
            if(a.t != b.t) return a.t < b.t;
            return a.l > b.l;
        });
    solve(1);
//    for(int i = 0; i <= N; ++i) {
//        cout << dp[arr[i].l][1] << ' ';
//    }
    cout << max(dp[S][0], dp[S][1]);
    return 0;
}

Compilation message (stderr)

salesman.cpp: In function 'void init(int, int, int)':
salesman.cpp:28:19: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   28 |     int mid = str + ed >> 1;
      |               ~~~~^~~~
salesman.cpp: In function 'void update(int, int, int, int, int)':
salesman.cpp:40:19: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   40 |     int mid = str + ed >> 1;
      |               ~~~~^~~~
salesman.cpp: In function 'int query(int, int, int, int, int, int)':
salesman.cpp:51:19: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   51 |     int mid = str + ed >> 1;
      |               ~~~~^~~~

• Subtask 1: 62 / 100