Submission #438054

# Submission time Handle Problem Language Result Execution time Memory
438054 2021-06-27T13:29:46 Z cheeheng Rainforest Jumps (APIO21_jumps) C++14
4 / 100
2165 ms 83492 KB
#include "jumps.h"
#include <bits/stdc++.h>
using namespace std;

typedef pair<int, int> ii;

int nextGreater[200005][20];
int prevGreater[200005][20];
int indx[200005];
int log2_[200005];
ii val[200005][20];
int best[200005][20];
int A1[200005];

int M;

void init2(){
    for(int i = 0; i < M; i ++){
        val[i][0] = ii(A1[i], i);
    }

    for(int k = 1; k < 20; k ++){
        for(int i = 0; i <= M-(1<<k); i ++){
            val[i][k] = max(val[i][k-1], val[i+(1<<(k-1))][k-1]);
        }
    }

    log2_[1] = 0;
    for(int i = 2; i <= M; i ++){
        log2_[i] = log2_[i>>1] + 1;
    }
}

ii findMax(int l, int r){
    int k = log2_[r-l+1];
    return max(val[l][k], val[r-(1<<k)+1][k]);
}

void init(int N, std::vector<int> H){
    M = N;

    for(int i = 0; i < N; i ++){
        A1[i] = H[i];
    }

    init2();

    for(int i = 0; i < N; i ++){
        nextGreater[i][0] = N;
        prevGreater[i][0] = -1;
    }

    vector<ii> stack1 = vector<ii>();
    for(int i = 0; i < N; i ++){
        while(!stack1.empty()){
            ii temp = stack1.back();

            if(temp.first < H[i]){
                nextGreater[temp.second][0] = i;
                stack1.pop_back();
            }else{
                break;
            }
        }
        stack1.emplace_back(H[i], i);
    }

    stack1 = vector<ii>();
    for(int i = N-1; i >= 0; i --){
        while(!stack1.empty()){
            ii temp = stack1.back();

            if(temp.first < H[i]){
                prevGreater[temp.second][0] = i;
                stack1.pop_back();
            }else{
                break;
            }
        }
        stack1.emplace_back(H[i], i);
    }

    /*for(int i = 0; i < N; i ++){
        printf("nextGreater[%d]=%d\n", i, nextGreater[i][0]);
    }

    for(int i = 0; i < N; i ++){
        printf("prevGreater[%d]=%d\n", i, prevGreater[i][0]);
    }*/

    for(int k = 1; k < 20; k ++){
        for(int i = 0; i < N; i ++){
            if(nextGreater[i][k-1] == N){
                nextGreater[i][k] = N;
            }else{
                nextGreater[i][k] = nextGreater[nextGreater[i][k-1]][k-1];
            }

            if(prevGreater[i][k-1] == -1){
                prevGreater[i][k] = -1;
            }else{
                prevGreater[i][k] = prevGreater[prevGreater[i][k-1]][k-1];
            }
        }
    }

    for(int i = 0; i < N; i ++){
        int X2 = i;
        int X3, X4;
        if(prevGreater[X2][0] == -1){
            X3 = nextGreater[X2][0];
            X4 = prevGreater[X2][0];
        }else if(nextGreater[X2][0] == M){
            X3 = prevGreater[X2][0];
            X4 = nextGreater[X2][0];
        }else if(A1[prevGreater[X2][0]] > A1[nextGreater[X2][0]]){
            X3 = prevGreater[X2][0];
            X4 = nextGreater[X2][0];
        }else{
            X3 = nextGreater[X2][0];
            X4 = prevGreater[X2][0];
        }
        best[i][0] = X3;
        if(best[i][0] == M){best[i][0] = -1;}
    }

    for(int k = 1; k < 20; k ++){
        for(int i = 0; i < N; i ++){
            if(best[i][k-1] == -1){
                best[i][k] = best[i][k-1];
            }else{
                best[i][k] = best[best[i][k-1]][k-1];
            }
        }
    }
}

int minimum_jumps(int A, int B, int C, int D){
    assert(0 <= A && A <= B && B < C && C <= D && D <= M-1);

    ii maxValCD = findMax(C, D);
    int maxIndxCD = prevGreater[maxValCD.second][0];
    //printf("maxValCD=%d\n", maxValCD);
    A = max(maxIndxCD+1, A);

    if(A > B){return -1;}

    ii maxValAB = findMax(A, B);
    int X = maxValAB.second;

    int cutOffIndx = X;
    for(int k = 19; k >= 0; k --){
        if(nextGreater[cutOffIndx][k] != M && nextGreater[cutOffIndx][k] < C){
            cutOffIndx = nextGreater[cutOffIndx][k];
        }
    }
    cutOffIndx = nextGreater[cutOffIndx][0];
    assert(cutOffIndx >= C && cutOffIndx <= D);

    int ans = 0;

    int X5 = X;
    int totalDist = 0;
    for(int k = 19; k >= 0; k --){
        int temp = best[X5][k];
        if(temp != -1 && temp != M && val[temp] < val[cutOffIndx]){
            totalDist += (1<<k);
            X5 = temp;
        }
    }

    int X2 = X;
    totalDist = max(0, totalDist-1);
    ans += totalDist;
    for(int k = 19; k >= 0; k --){
        int temp = best[X2][k];
        if(temp != -1 && temp != M && totalDist >= (1<<k)){
            totalDist -= (1<<k);
            X2 = temp;
        }
    }

    while(X2 < C){
        int X3, X4;
        if(prevGreater[X2][0] == -1){
            X3 = nextGreater[X2][0];
            X4 = prevGreater[X2][0];
        }else if(nextGreater[X2][0] == M){
            X3 = prevGreater[X2][0];
            X4 = nextGreater[X2][0];
        }else if(A1[prevGreater[X2][0]] > A1[nextGreater[X2][0]]){
            X3 = prevGreater[X2][0];
            X4 = nextGreater[X2][0];
        }else{
            X3 = nextGreater[X2][0];
            X4 = prevGreater[X2][0];
        }

        //printf("X2=%d; X3=%d; X4=%d\n", X2, X3, X4);
        if(X4 >= C && X4 <= D){
            X2 = X4;
        }else if(A1[X3] > maxValCD.first){
            X2 = X4;
        }else{
            X2 = X3;
        }
        //printf("X2=%d\n", X2);
        ans ++;
        assert(X2 >= 0 && X2 < M);
    }

    return ans;
}

Compilation message

jumps.cpp: In function 'void init(int, std::vector<int>)':
jumps.cpp:109:17: warning: variable 'X4' set but not used [-Wunused-but-set-variable]
  109 |         int X3, X4;
      |                 ^~
# Verdict Execution time Memory Grader output
1 Correct 1 ms 328 KB Output is correct
2 Correct 1 ms 328 KB Output is correct
3 Correct 297 ms 66352 KB Output is correct
4 Correct 2165 ms 83372 KB Output is correct
5 Correct 1401 ms 42120 KB Output is correct
6 Correct 1703 ms 83388 KB Output is correct
7 Correct 1269 ms 57060 KB Output is correct
8 Correct 1818 ms 83376 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 328 KB Output is correct
2 Correct 1 ms 328 KB Output is correct
3 Correct 1 ms 328 KB Output is correct
4 Correct 1 ms 328 KB Output is correct
5 Runtime error 7 ms 456 KB Execution killed with signal 6
6 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 1 ms 328 KB Output is correct
2 Correct 1 ms 328 KB Output is correct
3 Correct 1 ms 328 KB Output is correct
4 Correct 1 ms 328 KB Output is correct
5 Runtime error 7 ms 456 KB Execution killed with signal 6
6 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 1 ms 328 KB Output is correct
2 Correct 1 ms 328 KB Output is correct
3 Correct 1 ms 328 KB Output is correct
4 Correct 1 ms 328 KB Output is correct
5 Correct 166 ms 65684 KB Output is correct
6 Correct 229 ms 81668 KB Output is correct
7 Correct 112 ms 41908 KB Output is correct
8 Correct 234 ms 81796 KB Output is correct
9 Correct 15 ms 12488 KB Output is correct
10 Correct 275 ms 81820 KB Output is correct
11 Correct 257 ms 83372 KB Output is correct
12 Correct 256 ms 82884 KB Output is correct
13 Correct 231 ms 82824 KB Output is correct
14 Correct 221 ms 81668 KB Output is correct
15 Incorrect 237 ms 83492 KB Output isn't correct
16 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 1 ms 328 KB Output is correct
2 Correct 1 ms 284 KB Output is correct
3 Correct 1 ms 328 KB Output is correct
4 Runtime error 154 ms 75192 KB Execution killed with signal 6
5 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 1 ms 328 KB Output is correct
2 Correct 1 ms 284 KB Output is correct
3 Correct 1 ms 328 KB Output is correct
4 Runtime error 154 ms 75192 KB Execution killed with signal 6
5 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 1 ms 328 KB Output is correct
2 Correct 1 ms 328 KB Output is correct
3 Correct 297 ms 66352 KB Output is correct
4 Correct 2165 ms 83372 KB Output is correct
5 Correct 1401 ms 42120 KB Output is correct
6 Correct 1703 ms 83388 KB Output is correct
7 Correct 1269 ms 57060 KB Output is correct
8 Correct 1818 ms 83376 KB Output is correct
9 Correct 1 ms 328 KB Output is correct
10 Correct 1 ms 328 KB Output is correct
11 Correct 1 ms 328 KB Output is correct
12 Correct 1 ms 328 KB Output is correct
13 Runtime error 7 ms 456 KB Execution killed with signal 6
14 Halted 0 ms 0 KB -