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

const fi='';
      fo='';
      maxn=1000010;
var n,res,m:longint;
    re,mm,s:int64;
    a,st,pos,d,f:array[0..maxn] of longint;

procedure doc;
var i:longint;
begin
     read(n,m);
     for i:=1 to n do
     begin
          read(a[i]); re:=re+a[i];
     end;
end;

procedure timmin;
var i,l,r:longint;
begin
     st[0]:=-1; l:=1; r:=0;
     for i:=1 to n do
     begin
          while (a[i]<=st[r]) and (r>=l) do r:=r-1;
          r:=r+1;
          st[r]:=a[i];
          pos[r]:=i;
          while i-pos[l]>m-1 do l:=l+1;
          d[i]:=st[l];
     end;
end;

procedure tinh;
var i,j:longint;
begin
     mm:=m;
     res:=1; f[1]:=m;
     for i:=m+1 to n do
     begin
          j:=res-1;
          while (j>0) and (d[f[j+1]]<=d[i]) and (f[j]+m>=i) and (d[f[j]]>=d[f[j+1]]) do j:=j-1;
          res:=j+2;
          f[res]:=i;
     end;
     s:=mm*d[f[1]];
     for i:=2 to res do
     begin
          s:=s+(f[i]-f[i-1])*d[f[i]];
          j:=d[f[i]]-d[f[i-1]];
          if j>0 then s:=s+(mm-f[i]+f[i-1])*j;
     end;
     writeln(re-s);
     writeln(res);
end;

begin
     assign(input,fi); reset(input);
     assign(output,fo); rewrite(output);
     doc;
     timmin;
     tinh;
     close(input); close(output);
end.

Code mẫu của RR

#include <iostream>
#include <algorithm>
#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 MAXN 1100111
using namespace std;

int debug=0;
//Buffer reading
int INP,AM;
#define BUFSIZE (1<<10)
char BUF[BUFSIZE+1], *inp=BUF;
#define GETCHAR(INP) { \
    if(!*inp) { \
        fread(BUF,1,BUFSIZE,stdin); \
        inp=BUF; \
    } \
    INP=*inp++; \
}
#define DIG(a) (((a)>='0')&&((a)<='9'))
#define GN(j) { \
    AM=0;\
    GETCHAR(INP); while(!DIG(INP) && INP!='-') GETCHAR(INP);\
    if (INP=='-') {AM=1;GETCHAR(INP);} \
    j=INP-'0'; GETCHAR(INP); \
    while(DIG(INP)){j=10*j+(INP-'0');GETCHAR(INP);} \
    if (AM) j=-j;\
}
//Buffer reading

int n,x,a[MAXN],l[MAXN],r[MAXN],last[MAXN],h[MAXN];

void input() {
    GN(n); GN(x);
    FOR(i,1,n) GN(a[i]);
    while (n%x) {
        n++;
        a[n]=0;
    }
}

void init() {
    FOR(i,0,n/x-1) {
        int u=i*x+1;
        l[u]=a[u];
        u+=x-1;
        r[u]=a[u];
    }

    FOR(i,1,n)
        if (!l[i]) l[i]=min(l[i-1],a[i]);
    FORD(i,n,1)
        if (!r[i]) r[i]=min(r[i+1],a[i]);

    if (debug) {
        FOR(i,1,n) cout<<l[i]<<" "; cout<<endl;
        FOR(i,1,n) cout<<r[i]<<" "; cout<<endl;
    }
}

void solve() {
    FOR(i,x,n)
        last[i]=min(l[i],r[i-x+1]);

    memset(l,-1,sizeof l);
    memset(r,-1,sizeof r);

    FOR(i,0,n/x-1) {
        int u=i*x+1;
        l[u]=last[u];
        u+=x-1;
        r[u]=last[u];
    }

    if (debug) {
        FOR(i,1,n) cout<<last[i]<<" "; cout<<endl;
    }

    FOR(i,1,n)
        if (l[i]==-1) l[i]=max(l[i-1],last[i]);
    FORD(i,n,1)
        if (r[i]==-1) r[i]=max(r[i+1],last[i]);

    long long res=0LL;
    FOR(i,1,n) h[i]=max(l[i+x-1],r[i]);
    if (debug) {
        cout<<endl;
        FOR(i,1,n) cout<<l[i]<<" "; cout<<endl;
        FOR(i,1,n) cout<<r[i]<<" "; cout<<endl;
        FOR(i,1,n) cout<<h[i]<<" "; cout<<endl;
        cout<<endl;
    }
    FOR(i,1,n) res+=a[i]-h[i];
    cout<<res<<endl;

    int cnt=0,u=h[n],ok=n+1;
    FORD(i,n,1)
    if (a[i])
    if (i<ok || h[i]!=u) {
        cnt++;
        u=h[i]; ok=i-x+1;
    }
    cout<<cnt;
}

int main() {
    input();
    init();
    solve();
    return 0;
}

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);
}

const int bfsz = 1 << 16;
char bf[bfsz + 5];
int rsz = 0;
int ptr = 0;
char gc() {
    if (rsz <= 0) {
        ptr = 0;
        rsz = (int) fread(bf, 1, bfsz, stdin);
        if (rsz <= 0)
            return EOF;
    }
    --rsz;
    return bf[ptr++];
}
void ga(char &c) {
    c = EOF;
    while (!isalpha(c))
        c = gc();
}
int gs(char s[]) {
    int l = 0;
    char c = gc();
    while (isspace(c))
        c = gc();
    while (c != EOF && !isspace(c)) {
        s[l++] = c;
        c = gc();
    }
    s[l] = '\0';
    return l;
}
template<class T> bool gi(T &v) {
    v = 0;
    char c = gc();
    while (c != EOF && c != '-' && !isdigit(c))
        c = gc();
    if (c == EOF)
        return false;
    bool neg = c == '-';
    if (neg)
        c = gc();
    while (isdigit(c)) {
        v = v * 10 + c - '0';
        c = gc();
    }
    if (neg)
        v = -v;
    return true;
}

typedef pair<int, int> II;
const ld PI = acos(-1.0);
const ld eps = 1e-9;
const int dr[] = { -1, 0, +1, 0, 1, 1, -1, -1 };
const int dc[] = { 0, +1, 0, -1, 1, -1, 1, -1 };
const int inf = (int) 1e9 + 5;
const ll linf = (ll) 1e16 + 5;
const int mod = (ll) (1e9 + 7 + eps);
#define ok puts("ok")
#define maxn 2000005

int n, a[maxn], l[maxn], r[maxn], c[maxn], m;
ll res = 0, ret = 0;

int main(){
//  freopen("in.txt", "r", stdin);

    gi(n); gi(m);
    For(i, 1, n) gi(a[i]);
    a[0] = a[n + 1] = -1; c[0] = c[n + 1] = -1;
    For(i, 1, n){
        l[i] = i;
        while(a[l[i] - 1] >= a[i]) l[i] = l[l[i] - 1];
    }

    Ford(i, n, 1){
        r[i] = i;
        while(a[r[i] + 1] >= a[i]) r[i] = r[r[i] + 1];
    }

    int start = 1, u;
    For(i, 1, n){
        if(r[i] - l[i] < m - 1 || start > i) continue;
        int finish = r[i];
        u = i;
        while(u < r[i] && a[u + 1] == a[i]) u++;
        if(finish - u >= m) finish = u;
        For(j, start, finish){
            res += a[j] - a[i];
            c[j] = a[i];
        }
        start = finish + 1;
    }

    int i, j;
    for(i = 1; i <= n; i = j){
        for(j = i; j <= n && c[j] == c[i]; j++);
        ret += (j - i + m - 1) / m;
    }

    cout << res << endl << ret << endl;


    return 0;
}