#include<bits/stdc++.h>
#include <clocale>
using namespace std;
#define int long long
#define endl '\n'
void solve();
signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int tt = 1;
    //cin >> tt;
    while (tt--)solve();
    return 0;
}

const int nn = 111;
struct lc
{
    int x, y, z;
};
char g[nn][nn][nn];
int l, r, c;
lc s;
queue<pair<lc, int>> q;
int dx[4] = { -1,0,1,0 }, dy[4] = { 0,1,0,-1 }, dz[3] = { -1,0,1 };
void solve()
{
    while (cin >> l >> r >> c)
    {
        if (!l && !r && !c)return;
        for (int i = 1; i <= l; i++)
            for (int j = 1; j <= r; j++)
                for (int k = 1; k <= c; k++)
                    cin >> g[i][j][k];

        for (int i = 1; i <= l; i++)
            for (int j = 1; j <= r; j++)
                for (int k = 1; k <= c; k++)
                    if (g[i][j][k] == 'S')
                        s.x = j, s.y = k, s.z = i, g[i][j][k] = '#';

        queue<pair<lc, int>>().swap(q);
        q.push({ s,0 });
        while (!q.empty())
        {
            lc k = q.front().first;
            int cnt = q.front().second;
            q.pop();
            int x = k.x, y = k.y, z = k.z;
                for (int j = 0; j < 4; j++)
                {
                    int xx = x + dx[j], yy = y + dy[j], zz = z + dz[1];
                    if (xx<1 || xx>r || yy<1 || yy>c || zz<1 || zz>l || g[zz][xx][yy] == '#')continue;
                    else
                    {
                        if (g[zz][xx][yy] == 'E')
                        {
                            cout << "Escaped in " << cnt + 1 << " minute(s)." << endl;
                            goto loop;
                        }
                        else
                        {
                            q.push({ {xx,yy,zz},cnt + 1 });
                            g[zz][xx][yy] = '#';
                        }
                    }
                }
                for (int i = 0; i < 3; i++)
                {
                    if (i == 1)continue;
                    int zz = z + dz[i];
                    if (zz<1 || zz>l || g[zz][x][y] == '#')continue;
                    else
                    {
                        if (g[zz][x][y] == 'E')
                        {
                            cout << "Escaped in " << cnt + 1 << " minute(s)." << endl;
                            goto loop;
                        }
                        else
                        {
                            q.push({ {x,y,zz},cnt + 1 });
                            g[zz][x][y] = '#';
                        }
                    }
                }
        }
        cout << "Trapped!" << endl;
    loop:;
    }
}

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'
void solve();
signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int tt = 1;
    //cin >> tt;
    while(tt--)solve();
    return 0;
}

void solve()
{
    int n;
    int m = -1e18,deep = 0;
    cin>>n;
    vector<int> a(n+111);
    for(int i = 1;i<=n;i++)cin>>a[i];
    int len = 1;
    for(int i = 1, j = 1;i<=n;)
    {
        int res = 0;
        while(j<=n&&j-i<len)res+=a[j],j++;
        //m = max(m,res);
        if(res>m)m = res, deep = len;
        i = j;
        len*=2;
    }
    int cnt = 0;
    while(deep)deep/=2,cnt++;
    cout<<cnt;
}

#include<bits/stdc++.h>
using namespace std;
#define int long long 
#define endl '\n'
void solve();
signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int tt = 1;
    //cin>>tt;
    while(tt--)solve();
    return 0;
}

char g[1111][1111];
#define pii pair<int,int>
#define ft first
#define sd second
queue<pii> q;
int dx[4] = {-1,0,1,0}, dy[4] = {0,1,0,-1};

void solve()
{
    int n;
    cin>>n;
    for(int i = 1;i<=n;i++)
    for(int j = 1;j<=n;j++)
    cin>>g[i][j];

    int res = 0;
    for(int i = 1;i<=n;i++)
    for(int j = 1;j<=n;j++)
    {       
        if(g[i][j]=='#')
        {
            q.push({i,j});
            g[i][j] = '*';
            int cnt = 0;
            int ti = 0;
            int c = 0;
            while(q.size())
            {
                int x = q.front().ft, y = q.front().sd;
                q.pop();
                ti++;
                cnt = 0;
                // if(g[i][j]=='#')
                // cnt++,g[i][j] = '*';
                //else continue;
                for(int i = 0;i<4;i++)
                {
                    int xx = x + dx[i], yy = y + dy[i];
                    if(xx<1||xx>n||yy<1||yy>n)continue;
                    if(g[xx][yy] == '.')cnt=true;
                    if(g[xx][yy] == '#')
                    {
                        q.push({xx,yy});
                        g[xx][yy] = '*';
                    }
               }
               //cout<<c<<' '<<cnt<<endl;
               c+=cnt;
               //if(!cnt)g[x]
            }
            //cout<<c<<' '<<ti<<endl;
            if(c==ti)res++;
        }

    }
    cout<<res;
}

#include<iostream>
#include <locale>
using namespace std;
const int nn = 111111;
int e[nn],ne[nn],idx = 0;
void add_head(int x)
{
    e[++idx] = x;
    ne[idx] = ne[0];
    ne[0] = idx;
}
void dlt(int k)
{
    ne[k] = ne[ne[k]];
}
void insert(int k,int x)
{
    e[++idx] = x;
    ne[idx] = ne[k];
    ne[k] = idx;
}
int main()
{
    int m;
    cin>>m;
    while(m--)
    {
        char op; int k, x;
        cin>>op;
        if(op=='H')
        {
            cin>>x;
            add_head(x);
        }
        else if(op=='D')
        {
            cin>>k;
            dlt(k);
        }
        else 
        {
            cin>>k>>x;
            insert(k,x);
        }
    }
    for(int i = ne[0];i;i=ne[i])
    cout<<e[i]<<' ';
}

自己非常巧妙地写了一个映射

#include<bits/stdc++.h>
using namespace std;
const int N = 1e4 + 10;
int a[N], b[N];
int main()
{
    int n, cnt = 0;
    cin >> n;
    for (int i = 1; i <= n; i++)
        cin >> a[i], b[a[i]] = i;

    for (int i = 1; i <= n; i++)
        if (a[i] != i)
            swap(a[b[i]], a[i]),
            swap(b[a[b[i]]], b[i]),
            cnt++;

    cout << cnt;
}

省略掉映射b数组

#include<bits/stdc++.h>
using namespace std;
const int N = 1e4 + 10;
int a[N], b[N];
int main()
{
    int n, cnt = 0;
    cin >> n;
    for (int i = 1; i <= n; i++) cin >> a[i];

    for (int i = 1; i <= n; i++)
        while(a[i]!=i)swap(a[i], a[a[i]]), cnt++;

    cout << cnt;
}

#include<bits/stdc++.h>
using namespace std;
#define int long long 
#define endl '\n'
void solve();
signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int tt = 1;
    //cin>>tt;
    while (tt--)solve();
    return 0;
}

#define pii pair<int,int>
#define ft first
#define sd second

const int nn = 111;
int n, m;
int dx[4] = { -1,0,1,0 }, dy[4] = { 0,1,0,-1 };

void solve()
{
    int n, m;
    while (cin >> m >> n)
    {
        if (!n || !m)return;
        int cnt = 0;
        pii s;
        char g[nn][nn] = {};
        bool t[nn][nn] = {};
        for (int i = 1; i <= n; i++)cin >> &g[i][1];

       // for (int i = 1; i <= n; i++)for (int j = 1; j <= m; j++)cout << g[i][j] << " \n"[j == m];

          for(int i = 1;i<=n;i++)
          for(int j = 1;j<=m;j++)
          if(g[i][j]=='@')s = {i,j};

          t[s.ft][s.sd] = true;
          queue<pii> q;
          q.push(s);

          while(!q.empty())
          {
              auto k = q.front();
              q.pop();
              int x = k.ft , y = k.sd;
              for(int i = 0;i<4;i++)
              {
                  int xx = x+dx[i],yy = y+dy[i];
                  if (xx<1 || xx>n || yy<1 || yy>m || g[xx][yy] == '#' || t[xx][yy])continue;
                  t[xx][yy] = true;
                  cnt++;
                  q.push({xx,yy});
              }
          }
          cout<<cnt+1<<endl;
    }
}

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'
void solve();
signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int tt = 1;
    cin >> tt;
    while (tt--)solve();
    return 0;
}


#define pii pair<int,int>
#define ft first
#define sd second

void solve()
{
    int r, c;
    pii s, e;
    cin >> r >> c;
    vector<vector<char> > g(r + 1, vector<char>(c + 1));
    for (int i = 1; i <= r; i++)
        for (int j = 1; j <= c; j++)
            cin >> g[i][j];

    for(int i = 1;i<=r;i++)
        for (int j = 1; j <= c; j++)
        {
            if (g[i][j] == 'S')s = { i,j };
            if (g[i][j] == 'E')e = { i,j };
        }

    queue<pii> q;
    vector<vector<int> >dis(r + 1, vector<int>(c + 1, -1));
    dis[s.ft][s.sd] = 0;
    q.push(s);
    int dx[4] = { -1,0,+1,0 }, dy[4] = { 0,+1,0,-1 };
    while (q.size())
    {
        pii k = q.front();
        q.pop();
        int x = k.ft, y = k.sd;
        for (int i = 0; i < 4; i++)
        {
            int xx = x + dx[i], yy = y + dy[i];
            if (xx<1 || xx>r || yy<1 || yy>c || dis[xx][yy] != -1 || g[xx][yy] == '#')continue;
            dis[xx][yy] = dis[x][y] + 1;
            q.push({ xx,yy });
        }
    }
    if (dis[e.ft][e.sd] == -1)cout << "oop!" << endl;
    else cout << dis[e.ft][e.sd] << endl;
}

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'
void solve();
signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int tt = 1;
    //cin >> tt;
    while (tt--)solve();
    return 0;
}


#define pii pair<int,int>
#define ft first
#define sd second
vector<pii> v;
int cnt[111111];
bool t[111111];
const int T = 1e5 + 11;
void solve()
{
    int n, d, k;
    cin >> n >> d >> k;
    for (int i = 1; i <= n; i++)
    {
        int a, b;
        cin >> a >> b;
        v.emplace_back(a, b);
    }
    sort(v.begin(), v.end());
    for (int i = 0, j = 0; i < v.size() && j < v.size(); i++)
    {
        cnt[v[i].sd]++;
        while (v[i].ft - v[j].ft >= d)
        {
            cnt[v[j].sd]--;
            j++;
        }
        if (cnt[v[i].sd] >= k)t[v[i].sd] = true;
    }
    for (int i = 0; i <= T; i++)
        if (t[i])cout << i << endl;
}

#include<bits/stdc++.h>
using namespace std;
#define int long long 
#define endl '\n'
void solve();
signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int tt = 1;
    //cin >> tt;
    while (tt--)solve();
    return 0;
}

#define pii pair<int,int>
#define ft first
#define sd second
const int nn = 1e5 + 11;
pii a[nn];
int last[nn], sc[nn];
bool st[nn];
int n, m, ti;
void solve()
{
    cin >> n >> m >> ti;
    for (int i = 0; i < m; i++)cin >> a[i].ft >> a[i].sd;
    sort(a, a + m);

    //for(int i = 0;i<m;i++)cout<<a[i].ft<<' '<<a[i].sd<<endl;

    for (int i = 0; i < m; )
    {
        int j = i;
        while (j < m && a[i] == a[j])j++;
        int t = a[i].ft, id = a[i].sd;

    //  cout<<sc[id]<<"  "<<id<<"  "<<t<<endl;

        sc[id] -= t - last[id] - 1;
        if (sc[id] < 0)sc[id] = 0;
        if (sc[id] <= 3)st[id] = false;
        last[id] = t;
        sc[id] += (j - i) * 2;
        if (sc[id] > 5) st[id] = true;

        i = j;
    }

    //for (int i = 0; i < n; i++)cout << sc[i] << " \n"[i == n - 1];

    for (int i = 0; i <= n; i++)
    {
        if (last[i] < ti)sc[i] -= ti - last[i];
        if (sc[i] <= 3)st[i] = false;
    }
    int res = 0;
    for (int i = 0; i <= n; i++)res += st[i];
    cout << res;
}

#include<bits/stdc++.h>
using namespace std;
#define int long long 
#define endl '\n'
void solve();
signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int tt = 1;
    //cin >> tt;
    while (tt--)solve();
    return 0;
}

#define lowbit(x) x&-x
#define pii pair<int,int>
#define ft first
#define sd second
int n;
vector<int>tr;
vector<int>sum;
void add(int x)
{
    for (int i = x; i <= n; i += lowbit(i))tr[i]++;
}
int ask(int x)
{
    int res = 0;
    for (int i = x; i; i -= lowbit(i))res += tr[i];
    return res;
}
int cmp(pii a, pii b)
{
    if (a.ft != b.ft)return a.ft > b.ft;
    else return a.sd > b.sd;
}
void solve()
{
    cin >> n;
    vector<pii> h(n + 1);
    tr.resize(n + 1);
    sum.resize(n + 1);
    for (int i = 1; i <= n; i++)
        cin >> h[i].ft, h[i].sd = i;

    sort(h.begin() + 1, h.end(), cmp);

    for (int i = 1; i <= n; i++)
    {
        int k = h[i].sd;
        sum[i] = ask(k);
        add(k);
    }
    tr.assign(n + 1, 0);
    for (int i = n; i > 0; i--)
    {
        int k = h[i].sd;
        sum[i] += ask(n) - ask(k);
        add(k);
    }
    int res = 0;
    for (int i = 1; i <= n; i++)
        res += (1 + sum[i]) * sum[i] / 2;
    cout << res;
}