Submission #626353

#	Time	Username	Problem	Language	Result	Execution time	Memory
626353		boris_mihov	Catfish Farm (IOI22_fish)	C++17	9 / 100	90 ms	10864 KiB

fish

#include "fish.h"
#include <algorithm>
#include <iostream>
#include <cassert>
#include <numeric>
#include <vector>

typedef long long llong;
const int MAXM = 300000 + 10;
const int MAXN = 3000 + 10;
const int INF  = 1e9;

int n, m;
struct Fish
{
    int x, y, w;
    inline friend bool operator < (const Fish &a, const Fish &b)
    {
        return a.x < b.x || (a.x == b.x && a.y < b.y);
    }

} fish[MAXM];

llong solveOdd()
{
    llong ans = 0;
    for (int i = 1 ; i <= m ; ++i)
    {
        ans += fish[i].w;
    }

    return ans;
}

llong solveX12()
{
    llong sum[2];
    sum[0] = sum[1] = 0;
    for (int i = 1 ; i <= m ; ++i)
    {
        --fish[i].x;
        sum[fish[i].x] += fish[i].w; 
    }

    if (n == 2)
    {
        return std::max(sum[0], sum[1]);
    }
    std::sort(fish+1, fish+1+m);
    int ptr0 = 1;
    int ptr1 = 1;
    
    while (ptr1 <= m && fish[ptr1].x == 0) ptr1++;
    if (ptr1 == m+1) return sum[0];
    
    sum[0] = 0;
    llong ans = sum[1];
    
    while (ptr0 <= m && fish[ptr0].x == 0)
    {
        sum[0] += fish[ptr0].w;
        while (ptr1 <= m && fish[ptr1].y <= fish[ptr0].y)
        {
            sum[1] -= fish[ptr1].w;
            ++ptr1;
        }

        ans = std::max(ans, sum[0] + sum[1]);
        ptr0++;
    }

    return ans;
}

llong dp2[MAXM];
llong solveY1()
{
    llong ans = 0;
    std::sort(fish+1, fish+1+m);
    fish[0].x = -1;
    
    for (int i = 1 ; i <= m ; ++i)
    {
        if (fish[i].x != fish[i-1].x + 1) dp2[i] = fish[i].w + dp2[i-1];
        else dp2[i] = std::max(dp2[i-2] + fish[i].w, dp2[i-1]);
    }
    return dp2[m];
}

llong solveNSmall()
{
    llong ans = 0;
    return ans;
}

llong max_weights(int N, int M, std::vector <int> X, std::vector <int> Y, std::vector <int> W) 
{
    n = N;
    m = M;
    bool isOdd = true;
    bool isX01 = true;
    bool isY0 = true;

    for (int i = 1 ; i <= m ; ++i)    
    {
        ++X[i-1];
        ++Y[i-1];
        fish[i].x = X[i-1];
        fish[i].y = Y[i-1];
        fish[i].w = W[i-1];
        isOdd &= (fish[i].x &1);
        isX01 &= (fish[i].x <= 2);
        isY0 &= (fish[i].y == 1);
    }
    
    if (isOdd) return solveOdd();
    if (isX01) return solveX12();
    if (isY0) return solveY1();
    return solveNSmall();
}

Compilation message (stderr)

fish.cpp: In function 'llong solveY1()':
fish.cpp:78:11: warning: unused variable 'ans' [-Wunused-variable]
   78 |     llong ans = 0;
      |           ^~~

• Subtask 1: 3 / 3
• Subtask 2: 6 / 6
• Subtask 3: 0 / 9
• Subtask 4: 0 / 14
• Subtask 5: 0 / 21
• Subtask 6: 0 / 17
• Subtask 7: 0 / 14
• Subtask 8: 0 / 16