奇升偶降

c++能透過，c wrong

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
    int n;
    while (cin >> n) {
        vector<int> odd, even;
        int x;
        for (int i = 0; i < n; i++) {
            cin >> x;
            if (i % 2 == 0) {
                odd.push_back(x);
            }
            else {
                even.push_back(x);
            }
        }
        sort(odd.begin(), odd.end());
        sort(even.begin(), even.end(), greater<int>());

        int i = 0, j = 0;
        bool first = true;
        while (i < odd.size() || j < even.size()) {
            if (i < odd.size()) {
                if (!first) cout << " ";
                cout << odd[i++];
                first = false;
            }
            if (j < even.size()) {
                cout << " " << even[j++];
            }
        }
        cout << endl;
    }
    return 0;
}

#include<stdio.h>
#define N 110

void f1(int s[], int len) {
    for (int i = 0; i < len - 1; i++) {
        for (int j = 0; j < len - 1 - i; j++) {
            if (s[j] >= s[j + 1]) {
                int temp = s[j];
                s[j] = s[j + 1];
                s[j + 1] = temp;
            }
        }
    }
}

void f2(int s[], int len) {
    for (int i = 0; i < len - 1; i++) {
        for (int j = 0; j < len - 1 - i; j++) {
            if (s[j] <= s[j + 1]) {
                int temp = s[j];
                s[j] = s[j + 1];
                s[j + 1] = temp;
            }
        }
    }
}

int main() {
    int n;
    while (scanf("%d", &n) == 1) {
        int a[N], b[N];
        int la = 0, lb = 0;

        for (int i = 0; i < n; i++) {
            int x;
            scanf("%d", &x);
            if (i % 2 == 0) {  // 奇數位
                a[la++] = x;
            }
            else {           // 偶數位
                b[lb++] = x;
            }
        }


        f1(a, la);
        f2(b, lb);


        int i;
        for (i = 0; i < la && i < lb; i++) {
            printf("%d %d ", a[i], b[i]);
        }


        if (la > lb) {
            printf("%d ", a[la - 1]);
        }
 printf("\n");
      
    }

    return 0;
}