Submission #1301017

#	Time	Username	Problem	Language	Result	Execution time	Memory
1301017		tamir1	Obstacles for a Llama (IOI25_obstacles)	C++20	Compilation error	0 ms	0 KiB

obstacles

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

vector<int> T, H;
int N, M;
vector<int> max_reach; // max row reachable from row 0 in each column

void initialize(vector<int> _T, vector<int> _H) {
    T = _T;
    H = _H;
    N = T.size();
    M = H.size();
    
    // For each column, find the highest row that is free
    max_reach.assign(M, -1);
    for (int j = 0; j < M; j++) {
        int r = -1;
        for (int i = 0; i < N; i++) {
            if (T[i] > H[j]) r = i;
        }
        max_reach[j] = r;
    }
    
    // Make max_reach prefix maximum for fast queries
    for (int j = 1; j < M; j++) {
        max_reach[j] = max(max_reach[j], max_reach[j-1]);
    }
}

bool can_reach(int L, int R, int S, int D) {
    if (S > D) swap(S, D); // always go left-to-right
    int highest_row = (L == 0 ? max_reach[D] : max_reach[D] - max_reach[L-1]);
    // Check if there's a connected path from row 0 through columns L..R
    // If highest_row >= 0, path exists
    return (highest_row >= 0);
}

// For local testing
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int Q;
    cin >> N >> M;
    vector<int> t(N), h(M);
    for (int i = 0; i < N; i++) cin >> t[i];
    for (int j = 0; j < M; j++) cin >> h[j];
    initialize(t, h);
    cin >> Q;
    while (Q--) {
        int L, R, S, D;
        cin >> L >> R >> S >> D;
        cout << can_reach(L, R, S, D) << "\n";
    }
}

Compilation message (stderr)

/usr/bin/ld: /tmp/ccnYzDp6.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccfq0kRP.o:obstacles.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status