Submission #844998

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Source Code Expand

#include <bits/stdc++.h>

using namespace std;
#define mp make_pair
#define pb push_back
#define forn(i, n) for (int i = 0; i < (int)(n); ++i)
typedef long long LL;
typedef pair<int, int> PII;

int n;
int a[100005], ord[100005];

inline bool cmp(const int &lhs, const int &rhs) {
    return a[lhs] < a[rhs];
}

int main() {
    scanf("%d", &n);
    forn(i, n) scanf("%d", a + i);
    forn(i, n) ord[i] = i;
    sort(ord, ord + n, cmp);
    int cnt = 0;
    forn(i, n) if (ord[i] % 2 != i % 2) {
        ++cnt;
    }
    cout << cnt / 2 << endl;
    return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:18:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
                    ^
./Main.cpp:19:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     forn(i, n) scanf("%d", a + i);
                                  ^

Judge Result