Submission #1002537

#	Time	Username	Problem	Language	Result	Execution time	Memory
1002537		Ausp3x	Horses (IOI15_horses)	C++17	17 / 100	120 ms	42320 KiB

horses

// 人外有人，天外有天
// author: Ausp3x
 
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include "horses.h"
typedef long long             lng;
typedef unsigned int          uint;
typedef unsigned long long    ulng;
using namespace std;
using namespace __gnu_pbds;
 
int const INF32 = 0x3f3f3f3f;
lng const INF64 = 0x3f3f3f3f3f3f3f3f;
 
int const MOD = 1000000007;

lng modPow(lng x, lng y) {
    lng res = 1;
 
    while (y > 0) {
        if (y & 1) {
            res *= x;
            res %= MOD;
        }
 
        y >>= 1;
        x *= x;
        x %= MOD;
    }
 
    return (res + MOD) % MOD;
}

int nextPowOf2(int n) {
    n--;
    n |= n >> 1;
    n |= n >> 2;
    n |= n >> 4;
    n |= n >> 8;
    n |= n >> 16;
    n++;

    return n;
}

int N;
vector<int> X, Y;

int N2;
// actual prod, modulo prod
vector<pair<lng, lng>> x_seg;  
vector<int> i_seg;

lng queryXSeg(int l, int r, int opt) {
    l += N2;
    r += N2;

    lng res = 1;
    if (opt == 1) {
        while (l <= r) {
            if (l & 1) {
                res *= x_seg[l++].first;
                if (res > INF32)
                    res = INF32;
            } 
            if (!(r & 1)) {
                res *= x_seg[r--].first;
                if (res > INF32)
                    res = INF32;
            }

            l >>= 1;
            r >>= 1;
        }
    } else if (opt == 2) {
        while (l <= r) {
            if (l & 1)
                (res *= x_seg[l++].second) %= MOD;
            if (~r & 1)
                (res *= x_seg[r--].second) %= MOD;

            l >>= 1;
            r >>= 1;
        }
    }

    return res;
}

void updateISeg(int i) {
    i = (i + N2) >> 1;
    while (i > 0) {
        if (i_seg[2 * i + 1] == -1)
            i_seg[i] = i_seg[2 * i];
        else {
            if (Y[i_seg[2 * i]] >= queryXSeg(i_seg[2 * i] + 1, i_seg[2 * i + 1], 1) * Y[i_seg[2 * i + 1]])
                i_seg[i] = i_seg[2 * i];
            else
                i_seg[i] = i_seg[2 * i + 1];
        }

        i >>= 1;
    }

    return;
}

int init(int n, int x[], int y[]) {
    int N = n;
    X.resize(N);
    Y.resize(N);
    for (int i = 0; i < N; i++) {
        X[i] = x[i];
        Y[i] = y[i];
    }
    
    N2 = nextPowOf2(N);
    x_seg.resize(2 * N2, {-1, -1});
    for (int i = N2; i < N2 + N; i++) {
        x_seg[i].first = X[i - N2];
        x_seg[i].second = X[i - N2];
    }
    for (int d = N2 / 2; d >= 1; d >>= 1)
        for (int i = d; i < 2 * d; i++) {
            if (x_seg[2 * i + 1].first == -1)
                x_seg[i] = x_seg[2 * i];
            else {
                x_seg[i].first = x_seg[2 * i].first * x_seg[2 * i + 1].first;
                if (x_seg[i].first > INF32)
                    x_seg[i].first = INF32;
                (x_seg[i].second = x_seg[2 * i].second * x_seg[2 * i + 1].second) %= MOD;
            }
        }
    
    // for (auto [x, y] : x_seg)
    //     cout << x << ' ';
    // cout << endl;
    // for (auto [x, y] : x_seg)
    //     cout << y << ' ';
    // cout << endl;
    
    i_seg.resize(2 * N2, -1);
    for (int i = N2; i < N2 + N; i++)
        i_seg[i] = i - N2;
    for (int d = N2 / 2; d >= 1; d >>= 1)
        for (int i = d; i < 2 * d; i++) {
            if (i_seg[2 * i + 1] == -1)
                i_seg[i] = i_seg[2 * i];
            else {
                if (Y[i_seg[2 * i]] >= queryXSeg(i_seg[2 * i] + 1, i_seg[2 * i + 1], 1) * Y[i_seg[2 * i + 1]])
                    i_seg[i] = i_seg[2 * i];
                else
                    i_seg[i] = i_seg[2 * i + 1];
            }
        }
    
    // for (int x : i_seg)
    //     cout << x << ' ';
    // cout << endl;

    return queryXSeg(0, i_seg[1], 2) * Y[i_seg[1]] % MOD;
}

int updateX(int i, int v) {
    i = i + N2;
    x_seg[i] = {v, v};
    i >>= 1;
    while (i > 0) {
        if (x_seg[2 * i + 1].first == -1)
            x_seg[i] = x_seg[2 * i];
        else {
            x_seg[i].first = x_seg[2 * i].first * x_seg[2 * i + 1].first;
            if (x_seg[i].first > INF32)
                x_seg[i].first = INF32;
            (x_seg[i].second = x_seg[2 * i].second * x_seg[2 * i + 1].second) %= MOD;
        }

        i >>= 1;
    }

    updateISeg(i);

    return queryXSeg(0, i_seg[1], 2) * Y[i_seg[1]] % MOD;
}

int updateY(int i, int v) {
    Y[i] = v;

    updateISeg(i);

    return queryXSeg(0, i_seg[1], 2) * Y[i_seg[1]] % MOD;
}

/*
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int x[3] = {2, 1, 3};
    int y[3] = {3, 4, 1};
    cout << init(3, x, y) << endl;
    cout << updateY(1, 2) << endl;

    return 0;
}
//*/

/*
lng almostAllHorses = 1;
int getMaxValue(int opt) {
    if (opt == 1) {
        lng horses = 1;
        for (int i = 0; i < N; i++) {
            (horses *= X[i]) %= MOD;
            
            bool chk = true;
            lng cur = 1; 
            for (int j = i + 1; j < N; j++) {
                if (cur == INF32 || cur * X[j] > INF32) {
                    chk = false;
                    break;
                }
                cur *= X[j];
 
                if (cur * Y[j] > Y[i]) {
                    chk = false;
                    break;
                }
            }
                
            if (chk) {
                return horses * Y[i] % MOD;
            }
        }
    } else if (opt == 2) {
        lng horses = almostAllHorses;
        for (int i = max(N - 64, 0); i < N; i++) {
            (horses *= X[i]) %= MOD;
            
            bool chk = true;
            lng cur = 1; 
            for (int j = i + 1; j < N; j++) {
                if (cur == INF32 || cur * X[j] > INF32) {
                    chk = false;
                    break;
                }
                cur *= X[j];
 
                if (cur * Y[j] > Y[i]) {
                    chk = false;
                    break;
                }
            }
                
            if (chk) {
                return horses * Y[i] % MOD;
            }
        }
    }
 
    return -1;
}
 
bool allXG1 = true;
int init(int n, int x[], int y[]) {
    N = n;
    X.resize(n);
    Y.resize(n);
    for (int i = 0; i < N; i++) {
        if (i < N - 64)
            (almostAllHorses *= x[i]) %= MOD;
        
        if (x[i] < 2)
            allXG1 = false;

        X[i] = x[i];
        Y[i] = y[i];
    }
 
	return (allXG1 ? getMaxValue(2) : getMaxValue(1));
}
 
bool allValG1 = true;
int updateX(int pos, int val) {
    if (pos < N - 64) {
        (almostAllHorses *= modPow(X[pos], MOD - 2)) %= MOD;
        (almostAllHorses *= val) %= MOD;
    }

    if (val < 2)
        allValG1 = false;
    
    X[pos] = val;

	return (allXG1 && allValG1 ? getMaxValue(2) : getMaxValue(1));
}
 
int updateY(int pos, int val) {    
    Y[pos] = val;
 
	return (allXG1 && allValG1 ? getMaxValue(2) : getMaxValue(1));
}
//*/

Compilation message (stderr)

horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:110:9: warning: declaration of 'N' shadows a global declaration [-Wshadow]
  110 |     int N = n;
      |         ^
horses.cpp:47:5: note: shadowed declaration is here
   47 | int N;
      |     ^
horses.cpp:162:52: warning: conversion from 'lng' {aka 'long long int'} to 'int' may change value [-Wconversion]
  162 |     return queryXSeg(0, i_seg[1], 2) * Y[i_seg[1]] % MOD;
      |            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
horses.cpp: In function 'int updateX(int, int)':
horses.cpp:184:52: warning: conversion from 'lng' {aka 'long long int'} to 'int' may change value [-Wconversion]
  184 |     return queryXSeg(0, i_seg[1], 2) * Y[i_seg[1]] % MOD;
      |            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
horses.cpp: In function 'int updateY(int, int)':
horses.cpp:192:52: warning: conversion from 'lng' {aka 'long long int'} to 'int' may change value [-Wconversion]
  192 |     return queryXSeg(0, i_seg[1], 2) * Y[i_seg[1]] % MOD;
      |            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~

• Subtask 1: 17 / 17
• Subtask 2: 0 / 17
• Subtask 3: 0 / 20
• Subtask 4: 0 / 23
• Subtask 5: 0 / 23