Submission #1039864

#	Time	Username	Problem	Language	Result	Execution time	Memory
1039864		Zicrus	Horses (IOI15_horses)	C++17	17 / 100	60 ms	37492 KiB

horses

#include <bits/stdc++.h>
#include "horses.h"
using namespace std;

typedef long long ll;

ll n, pow2;
vector<ll> segMul, segMax;
vector<bool> segOF;
vector<ll> x, y;
vector<ll> lnk;
vector<ll> effY;

#define MOD (1000000007)

int getPrev2Id(int i) {
    // TODO (inc)
    // If no 2, return id 0
    // i can be negative!!!
    if (i < 0) return 0;
    i += pow2;
    while (segMul[i] == 1 && !segOF[i]) {
        if (!(i & 1)) {
            if ((i & (i-1)) == 0) return 0;
            i--;
        }
        i /= 2;
    }
    // now search down
    while (i < pow2) {
        if (segMul[2*i+1] == 1 && !segOF[2*i+1]) i = 2*i;
        else i = 2*i+1;
    }
    return i;
}

int getMax(ll low, ll high) {
    low += pow2; high += pow2;
    ll res = 0;
    while (low <= high) {
        if (low & 1) res = max(res, segMax[low++]);
        if (!(high & 1)) res = max(res, segMax[high--]);
        low /= 2; high /= 2;
    }
    return res;
}

void setX(int pos, int val) {
    if (val == x[pos]) return;
    int savedPos = pos;
    int old = x[pos];
    x[pos] = val;
    pos += pow2;
    segMul[pos] = val;
    pos /= 2;
    while (pos) {
        segMul[pos] = segMul[2*pos] * segMul[2*pos+1];
        if (segOF[2*pos] || segOF[2*pos+1] || segMul[pos] > MOD) {
            segMul[pos] %= MOD;
            segOF[pos] = true;
        }
        else {
            segOF[pos] = false;
        }
        pos /= 2;
    }
    pos = savedPos;

    if (val == 1) {
        ll prev2 = getPrev2Id(pos-1);
        lnk[prev2] = lnk[pos];
        effY[prev2] = getMax(prev2, lnk[prev2]-1);
        return;
    }
    if (old > 1) {
        effY[pos] = getMax(pos, lnk[pos]-1);
        return;
    }
    if (pos == 0) {
        effY[pos] = getMax(pos, lnk[pos]-1);
        return;
    }
    ll prev2 = getPrev2Id(pos-1);
    lnk[pos] = lnk[prev2];
    effY[pos] = getMax(pos, lnk[pos]-1);
    lnk[prev2] = pos;
    effY[prev2] = getMax(prev2, lnk[prev2]-1);
}

void setY(int pos, int val) {
    ll i = pos;
    y[i] = val;
    i += pow2;
    segMax[i] = val;
    i /= 2;
    while (i) {
        segMax[i] = max(segMax[2*i], segMax[2*i+1]);
        i /= 2;
    }

    ll prev2 = getPrev2Id(pos-1);
    effY[prev2] = getMax(prev2, lnk[prev2]-1);
}

int getOFId(int i = 1, ll prod = 1) {
    if (i >= pow2) return i-pow2;
    if (segOF[2*i+1] || segMul[2*i+1] * prod >= MOD) return getOFId(2*i+1, prod);
    return getOFId(2*i, prod * segMul[2*i+1]);
}

int getMulMod(int i) {
    int low = pow2, high = pow2+i;
    ll res = 1;
    while (low <= high) {
        if (low & 1) res = (res * segMul[low++]) % MOD;
        if (!(high & 1)) res = (res * segMul[high--]) % MOD;
        low /= 2; high /= 2;
    }
    return res % MOD;
}

int calc() {
    ll ofId = getOFId();
    ll mx = effY[ofId];
    ll offCnt = getMulMod(ofId);
    ll tCnt = 1;
    ll mxRes = (effY[ofId] * offCnt) % MOD;
    ofId++;
    if (!segOF[1]) {
        offCnt = 1;
        ofId = 0;
        mx = 0;
    }
    for (int i = ofId; i < n; i = lnk[i]) {
        offCnt *= x[i];
        offCnt %= MOD;
        tCnt *= x[i];
        ll val = tCnt * effY[i];
        if (val > mx) {
            mx = val;
            mxRes = (offCnt * effY[i]) % MOD;
        }
    }
    return mxRes;
}

int init(int N, int X[], int Y[]) {
	n = N; pow2 = 1ll << (ll)ceil(log2(n));
    x = vector<ll>(n);
    y = vector<ll>(n);
    lnk = vector<ll>(n);
    effY = vector<ll>(n);
    ll lastNon1 = n;
    for (int i = n-1; i >= 0; i--) {
        x[i] = X[i];
        y[i] = Y[i];
        lnk[i] = lastNon1;
        if (x[i] > 1) lastNon1 = i;
    }
    segMul = vector<ll>(2*pow2, 1);
    segMax = vector<ll>(2*pow2, 1);
    segOF = vector<bool>(2*pow2);
    for (int i = 0; i < n; i++) {
        segMul[pow2+i] = x[i];
        segMax[pow2+i] = y[i];
    }
    for (int i = pow2-1; i > 0; i--) {
        segMul[i] = segMul[2*i] * segMul[2*i+1];
        if (segOF[2*i] || segOF[2*i+1] || segMul[i] >= MOD) {
            segMul[i] %= MOD;
            segOF[i] = true;
        }
        segMax[i] = max(segMax[2*i], segMax[2*i+1]);
    }
    for (int i = 0; i < n; i = lnk[i]) {
        if (lnk[i] == i+1) effY[i] = y[i];
        else effY[i] = getMax(i, lnk[i]-1);
    }

    return calc();
}

int updateX(int pos, int val) {
    setX(pos, val);
	return calc();
}

int updateY(int pos, int val) {
    setY(pos, val);
	return calc();
}

Compilation message (stderr)

horses.cpp: In function 'int getPrev2Id(int)':
horses.cpp:21:7: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   21 |     i += pow2;
      |     ~~^~~~~~~
horses.cpp: In function 'int getMax(ll, ll)':
horses.cpp:45:12: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   45 |     return res;
      |            ^~~
horses.cpp: In function 'void setX(int, int)':
horses.cpp:51:20: warning: conversion from '__gnu_cxx::__alloc_traits<std::allocator<long long int>, long long int>::value_type' {aka 'long long int'} to 'int' may change value [-Wconversion]
   51 |     int old = x[pos];
      |                    ^
horses.cpp:53:9: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   53 |     pos += pow2;
      |     ~~~~^~~~~~~
horses.cpp: In function 'int getOFId(int, ll)':
horses.cpp:106:28: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
  106 |     if (i >= pow2) return i-pow2;
      |                           ~^~~~~
horses.cpp: In function 'int getMulMod(int)':
horses.cpp:112:15: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
  112 |     int low = pow2, high = pow2+i;
      |               ^~~~
horses.cpp:112:32: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
  112 |     int low = pow2, high = pow2+i;
      |                            ~~~~^~
horses.cpp:119:16: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
  119 |     return res % MOD;
      |                ^
horses.cpp: In function 'int calc()':
horses.cpp:125:27: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
  125 |     ll offCnt = getMulMod(ofId);
      |                           ^~~~
horses.cpp:134:18: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
  134 |     for (int i = ofId; i < n; i = lnk[i]) {
      |                  ^~~~
horses.cpp:134:40: warning: conversion from '__gnu_cxx::__alloc_traits<std::allocator<long long int>, long long int>::value_type' {aka 'long long int'} to 'int' may change value [-Wconversion]
  134 |     for (int i = ofId; i < n; i = lnk[i]) {
      |                                        ^
horses.cpp:144:12: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
  144 |     return mxRes;
      |            ^~~~~
horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:154:19: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
  154 |     for (int i = n-1; i >= 0; i--) {
      |                  ~^~
horses.cpp:167:22: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
  167 |     for (int i = pow2-1; i > 0; i--) {
      |                  ~~~~^~
horses.cpp:175:37: warning: conversion from '__gnu_cxx::__alloc_traits<std::allocator<long long int>, long long int>::value_type' {aka 'long long int'} to 'int' may change value [-Wconversion]
  175 |     for (int i = 0; i < n; i = lnk[i]) {
      |                                     ^

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