信息学奥赛课课通复习 U5.2

U5 数组

5.2.1 校门外的树

#include <bits/stdc++.h>
using namespace std;
int n, m;
bool arr[100005] = {true};
void edit(int l, int r)
{
    for (int i = l - 1; i < r; i++)
    {
        arr[i] = false;
    }
}
int main()
{
    memset(arr, 1, sizeof(arr));
    // freopen("tree1.in","r",stdin);
    // freopen("tree1.out","w",stdout);
    int ans = 0;
    cin >> n >> m;
    for (int i = 0; i < m; i++)
    {
        int l, r;
        cin >> l >> r;
        edit(l, r);
    }
    for (int i = 0; i < n; i++)
    {
        if (arr[i])
            ++ans;
    }
    cout << ans + 1 << endl;
}

---

5.2.2 高个子的人数

#include <bits/stdc++.h>
using namespace std;
vector<int> vct;
int main()
{
    int n;
    cin >> n;
    for (int i = 0; i < n; i++)
    {
        int x;
        cin >> x;
        vct.push_back(x);
    }
    int ans = 0;
    long long sum = accumulate(vct.begin(), vct.end(), 0.0);
    long double mean = sum / n;
    for (int i = 0; i < n; i++)
    {
        if (vct[i] > mean)
            ans++;
    }
    cout << ans << endl;
}

5.2.3 旗手

#include <bits/stdc++.h>
using namespace std;
int main()
{
    int n;
    cin >> n;
    int maxheight = -1, maxpos = -1;
    int arr[10005];
    for (int i = 0; i < n; i++)
    {
        cin >> arr[i];
        if (arr[i] > maxheight)
        {
            maxheight = arr[i];
            maxpos = i;
        }
    }
    cout << maxheight<<" ";
    for (int i = 0; i < n-1; i++)
    {
        if(i==maxpos-1)continue;
        if(i==maxpos)cout<<arr[0]<<" ";
        cout<<arr[i+1]<<" ";
    }
}