Lưu ý: Các code mẫu dưới đây chỉ mang tính tham khảo và có thể không AC được bài tập này

Code mẫu của flashmt

#include <iostream>
#include <algorithm>
using namespace std;

int n,x,curMax,curMin,ans,last,low[100100],high[100100];

int main()
{

    cin >> n >> curMax;
    curMin=curMax;
    for (int i=1;i<=n;i++) 
    {
        if (i<n) scanf("%d",&x);
        else x=1000111222;
        if (x>curMax) 
        {
            while (last && curMin<=low[last]) last--;
            low[++last]=curMin; high[last]=curMax;
            curMax=curMin=x;
        }
        else curMin=min(curMin,x);
    }
    for (int i=1;i<=last;i++) ans+=high[i]-max(low[i],high[i-1]);
    cout << ans << endl;
}

Code mẫu của ladpro98

#include <bits/stdc++.h>

using namespace std;

const int N = 100005;

int n;
int a[N], MAX[N];

int main() {
    ios::sync_with_stdio(0); cin.tie(0);
    cin >> n;
    for (int i = 1; i <= n; ++i) cin >> a[i];
    for (int i = 1; i <= n; ++i) {
        MAX[i] = MAX[i - 1];
        if (a[MAX[i]] < a[i]) MAX[i] = i;
    }
    int ans = 0, last = n, upperBound = 1e9 + 9;
    while (last > 0) {
        int maxV = min(a[MAX[last]], upperBound), maxPos = MAX[last];
        int minV = maxV;
        for (int i = maxPos + 1; i <= last; ++i) minV = min(minV, a[i]);
        ans += maxV - minV;
        upperBound = min(upperBound, minV);
        last = maxPos - 1;
    }
    cout << ans << endl;
    return 0;
}

Code mẫu của RR

//Written by RR
{$R+,Q+}
{$Mode objfpc}
{$inline on}
uses math;
const
  FINP          =       '';
  FOUT          =       '';
  MAXN          =       200111;

var
  f1,f2         :       text;
  n             :       longint;
  a,lowest      :       array[1..MAXN] of longint;
  c,typ         :       array[1..MAXN] of longint;

procedure openF;
    begin
      assign(f1,FINP); reset(f1);
      assign(f2,FOUT); rewrite(f2);
    end;
procedure closeF;
    begin
      close(f1);
      close(f2);
    end;

procedure inp;
    var
      i:longint;
    begin
      read(f1,n);
      for i:=1 to n do read(f1,a[i]);
    end;

procedure swap(var a,b:longint); inline;
    var
      tmp:longint;
    begin
      tmp:=a; a:=b; b:=tmp;
    end;

procedure sort(l,r:longint); inline;
    var
      i,j,mid,tmp:longint;
    begin
      i:=l; j:=r; mid:=c[l+random(r-l+1)];
      repeat
        while c[i]<mid do inc(i);
        while c[j]>mid do dec(j);
        if i<=j then
          begin
            swap(c[i],c[j]);
            swap(typ[i],typ[j]);
            inc(i); dec(j);
          end;
      until i>j;
      if i<r then sort(i,r);
      if l<j then sort(l,j);
    end;

procedure solve;
    var
      i,sl,save,sum:longint;
      res:int64;
    begin
      lowest[1]:=a[1];
      for i:=2 to n do
        lowest[i]:=max(lowest[i-1],a[i]);

      sl:=0;
      for i:=1 to n do
        if a[i]<lowest[i] then
          begin
            inc(sl); c[sl]:=a[i]; typ[sl]:=1;
            inc(sl); c[sl]:=lowest[i]; typ[sl]:=-1;
          end;
      sort(1,sl);

      save:=c[1]; typ[sl+1]:=1;
      res:=0; sum:=0;
      for i:=1 to sl do
        begin
          inc(sum,typ[i]);
          if (typ[i]=-1) and (sum=0) then
            begin
              inc(res,c[i]-save);
              save:=c[i+1];
            end;
        end;
      writeln(f2,res);
    end;

begin
  openF;
  inp;
  solve;
  closeF;
end.

Code mẫu của hieult

#include <set>
#include <map>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <cstdlib>
#include <cstring>
#include <sstream>
#include <iomanip>
#include <iostream>
#include <algorithm>
#include <ctime>
#include <deque>
#include <bitset>
#include <cctype>
#include <utility>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef unsigned int ui;
typedef unsigned long long ull;

#define Rep(i,n) for(int i = 0; i < (n); ++i)
#define Repd(i,n) for(int i = (n)-1; i >= 0; --i)
#define For(i,a,b) for(int i = (a); i <= (b); ++i)
#define Ford(i,a,b) for(int i = (a); i >= (b); --i)
#define Fit(i,v) for(__typeof((v).begin()) i = (v).begin(); i != (v).end(); ++i)
#define Fitd(i,v) for(__typeof((v).rbegin()) i = (v).rbegin(); i != (v).rend(); ++i)
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define sz(a) ((int)(a).size())
#define all(a) (a).begin(), (a).end()
#define ms(a,x) memset(a, x, sizeof(a))

template<class F, class T> T convert(F a, int p = -1) {
    stringstream ss;
    if (p >= 0)
        ss << fixed << setprecision(p);
    ss << a;
    T r;
    ss >> r;
    return r;
}
template<class T> T gcd(T a, T b) {
    T r;
    while (b != 0) {
        r = a % b;
        a = b;
        b = r;
    }
    return a;
}
template<class T> T lcm(T a, T b) {
    return a / gcd(a, b) * b;
}
template<class T> T sqr(T x) {
    return x * x;
}
template<class T> T cube(T x) {
    return x * x * x;
}
template<class T> int getbit(T s, int i) {
    return (s >> i) & 1;
}
template<class T> T onbit(T s, int i) {
    return s | (T(1) << i);
}
template<class T> T offbit(T s, int i) {
    return s & (~(T(1) << i));
}
template<class T> int cntbit(T s) {
    return s == 0 ? 0 : cntbit(s >> 1) + (s & 1);
}

typedef pair<int, int> II;
const ld PI = acos(-1.0);
const ld eps = 1e-9;
const int dr[] = { -1, 0, +1, 0 };
const int dc[] = { 0, +1, 0, -1 };
const int inf = (int) 1e9 + 5;
const ll linf = (ll) 1e16 + 5;
const ll mod = (ll) 1e9 + 7;

#define maxn 200005

int a[maxn], n;
vector<pair<int, int> > V;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
//    freopen("in.txt", "r", stdin);
    ll res = 0;
    cin >> n;
    For(i, 1, n) cin >> a[i];
    int MAX = 0;
    For(i, 1, n){
        MAX = max(MAX, a[i]);
        V.pb(mp(a[i], MAX));
    }

    sort(all(V));
    res = V[0].se - V[0].fi;

    MAX = V[0].se;
    For(i, 1, sz(V) - 1){
        res += max(0, V[i].se - max(V[i].fi, MAX));
        MAX = max(MAX, V[i].se);
    }

    cout << res << endl;

    return 0;
}

Code mẫu của ll931110

{$MODE DELPHI}
program TOINCSEQ;
const
  input  = '';
  output = '';
  maxn = 100000;
type
  rec = record
    inf,sup: integer;
  end;
var
  n: integer;
  a: array[1..maxn] of integer;
  stack: array[1..maxn] of rec;
  top,res: integer;

procedure init;
var
  f: text;
  i: integer;
begin
  assign(f, input);
    reset(f);

  readln(f, n);
  for i := 1 to n do read(f, a[i]);

  close(f);
end;

procedure push(v: rec);
begin
  inc(top);
  stack[top] := v;
end;

procedure pop;
begin
  dec(top);
end;

procedure solve;
var
  i: integer;
  v: rec;
begin
  top := 0;
  res := 0;
  i := 1;

  v.inf := 0;
  v.sup := 0;

  while (i < n) and (a[i] <= a[i + 1]) do
    begin
      v.sup := a[i + 1];
      inc(i);
    end;

  if i = n then exit;
  v.sup := a[i];
  v.inf := a[i + 1];

  repeat
    while (i <= n) and (v.sup >= a[i]) do
      begin
        if v.inf > a[i] then v.inf := a[i];
        inc(i);
      end;

    while (top > 0) and (v.inf < stack[top].inf) do pop;
    if top = 0 then push(v)
      else if v.inf > stack[top].sup then push(v) else stack[top].sup := v.sup;

    if i > n then break;

    v.sup := a[i];
    while (i < n) and (a[i] <= a[i + 1]) do
    begin
      v.sup := a[i + 1];
      inc(i);
    end;

    if i > n then break;
    v.inf := a[i];
  until i > n;

  while top > 0 do
    begin
      res := res + (stack[top].sup - stack[top].inf);
      pop;
    end;
end;

procedure printresult;
var
  f: text;
begin
  assign(f, output);
    rewrite(f);
    writeln(f, res);
  close(f);
end;

begin
  init;
  solve;
  printresult;
end.

Code mẫu của khuc_tuan

#include <iostream>
#include <cstdio>
#include <cstring>
#include <string>
#include <cmath>
#include <sstream>
#include <cstdlib>
#include <algorithm>
#include <map>
#include <set>
#include <queue>

using namespace std;

#define Rep(i,n) for(int i=0,lll=(n);i<lll;++i)
#define For(i,a,b) for(int i=(a),lll=(b);i<=lll;++i)
#define Ford(i,a,b) for(int i=(a),lll=(b);i>=lll;--i)
#define pb push_back
#define MP make_pair
#define fi first
#define se second

inline int nextint() { int x; scanf("%d", &x); return x; }

int n;
pair<int,int> a[100010];
int min_index[100010];

int main() {
    scanf("%d", &n);
    Rep(i,n) {
        scanf("%d", &a[i].fi);
        a[i].se = i;
    }
    sort( a, a + n);
    min_index[n-1] = a[n-1].se;
    Ford(i,n-2,0) min_index[i] = min( min_index[i+1], a[i].se);
    int max_index = -1, res = 0;
    Rep(i,n-1) {
        max_index = max( max_index, a[i].se);
        if(max_index > min_index[i+1]) res += a[i+1].fi - a[i].fi;
    }
    printf("%d\n", res);
    return 0;
}