Submission #1290838

#	Time	Username	Problem	Language	Result	Execution time	Memory
1290838		ecen30	Triple Peaks (IOI25_triples)	C++20	Compilation error	0 ms	0 KiB

triples

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

long long count_triples(vector<int> H) {
    int N = H.size();
    long long ans = 0;

    for (int i = 0; i < N; i++) {
        int d = H[i];          // want H[i] = k - i
        int k = i + d;         // implied k

        if (k >= N) continue;  // out of bounds → not a valid triple

        int hk = H[k];

        // Two possible choices of j:
        // Case 1: hk == x  => x = hk => j = i + hk, H[j] must be d - hk
        // Case 2: hk == d-x => x = d - hk => j = i + (d-hk), H[j] must be hk

        // Case 1:
        if (hk > 0 && hk < d) {
            int j = i + hk;
            if (j > i && j < k) {
                if (H[j] == d - hk) ans++;
            }
        }

        // Case 2:
        int x2 = d - hk;
        if (x2 > 0 && x2 < d) {
            int j = i + x2;
            if (j > i && j < k) {
                if (H[j] == hk) ans++;
            }
        }
    }

    return ans;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int mode;
    cin >> mode;

    if (mode == 1) {   // Part I
        int N;
        cin >> N;
        vector<int> H(N);
        for (int i = 0; i < N; i++) cin >> H[i];
        cout << count_triples(H) << "\n";
    }
    else {
        // Part II (construction) left empty intentionally
    }
    return 0;
}

Compilation message (stderr)

/usr/bin/ld: /tmp/ccNhU7EJ.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/cc2Xo1Ub.o:triples.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/ccNhU7EJ.o: in function `main':
grader.cpp:(.text.startup+0x197): undefined reference to `construct_range(int, int)'
collect2: error: ld returned 1 exit status