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

Code mẫu của RR

#include <sstream>
#include <iomanip>
#include <iostream>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#include <vector>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <string>
#include <deque>
#include <complex>

#define FOR(i,a,b) for(int i=(a),_b=(b); i<=_b; i++)
#define FORD(i,a,b) for(int i=(a),_b=(b); i>=_b; i--)
#define REP(i,a) for(int i=0,_a=(a); i<_a; i++)
#define FORN(i,a,b) for(int i=(a),_b=(b);i<_b;i++)
#define DOWN(i,a,b) for(int i=a,_b=(b);i>=_b;i--)
#define SET(a,v) memset(a,v,sizeof(a))
#define sqr(x) ((x)*(x))
#define ll long long
#define F first
#define S second
#define PB push_back
#define MP make_pair

#define DEBUG(x) cout << #x << " = "; cout << x << endl;
#define PR(a,n) cout << #a << " = "; FOR(_,1,n) cout << a[_] << ' '; cout << endl;
#define PR0(a,n) cout << #a << " = "; REP(_,n) cout << a[_] << ' '; cout << endl;
using namespace std;

//Buffer reading
int INP,AM,REACHEOF;
#define BUFSIZE (1<<12)
char BUF[BUFSIZE+1], *inp=BUF;
#define GETCHAR(INP) { \
    if(!*inp) { \
        if (REACHEOF) return 0;\
        memset(BUF,0,sizeof BUF);\
        int inpzzz = fread(BUF,1,BUFSIZE,stdin);\
        if (inpzzz != BUFSIZE) REACHEOF = true;\
        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;\
}
//End of buffer reading

const long double PI = acos((long double) -1.0);

int n, k, ln[3011];
set< pair<int,int> > s;
int side[3011][6011];

pair<int,int> get(int a, int b, int c) {
    return MP(c, b*2 - (a+b+c+n+1)%2);
}

bool inside(int i, int j) {
    if (i < 1 || i > n) return false;
    return (j >= 1) && (j <= ln[i]);
}

int getSide(int i, int j) {
    if (inside(i, j)) return side[i][j];
    else return 0;
}

int main() {
    scanf("%d%d", &n, &k);
    FOR(i,1,k) {
        int a, b, c;
        scanf("%d%d%d", &a, &b, &c);
        s.insert(get(a, b, c));
    }
    ln[n] = 1;
    FORD(i,n-1,1) ln[i] = ln[i+1] + 2;

    long long res = 0;
    FOR(i,1,n) {
        for(int j = 1; j <= ln[i]; j += 2) {
            if (s.find(MP(i,j)) != s.end()) {
                side[i][j] = 0;
            }
            else {
                if (s.find(MP(i-1,j+1)) != s.end()) side[i][j] = 1;
                else side[i][j] = 1 + min(getSide(i-1,j), getSide(i-1,j+2));
            }

            res += side[i][j];
        }
    }

    FORD(i,n,1) {
        for(int j = 2; j <= ln[i]; j += 2) {
            if (s.find(MP(i,j)) != s.end()) {
                side[i][j] = 0;
            }
            else {
                if (s.find(MP(i+1,j-1)) != s.end()) side[i][j] = 1;
                else side[i][j] = 1 + min(getSide(i+1, j), getSide(i+1, j-2));
            }

            res += side[i][j];
        }
    }
    cout << res << endl;
    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};
const int dc[] = { 0, +1, 0, -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 3005
#define maxe 40005

bool flag[maxn][maxn][2];
int n, num, f[maxn][maxn];

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

    gi(n); gi(num);
    int x, y, z;
    ms(flag, 0);
    Rep(run, num){
        gi(x); gi(y); gi(z);
        flag[z][y][(x + y + z + n + 1) & 1] = 1;
    }

    ll res = 0;
    ms(f, 0);
    Ford(i, n, 1){
        For(j, 1, n - i + 1){
            if(flag[i][j][1]) f[i][j] = 0;
            else{
                f[i][j] = min(f[i + 1][j - 1], f[i][j - 1]) + 1;
                if(flag[i][j - 1][0]) f[i][j] = 1;
                res += f[i][j];
            }
        }
    }

    ms(f, 0);
    For(i, 1, n) For(j, 1, n - i){
        if(flag[i][j][0]) f[i][j] = 0;
        else {
            f[i][j] = min(f[i - 1][j], f[i][j - 1]) + 1;
            if(flag[i][j][1]) f[i][j] = 1;
            res += f[i][j];
        }
    }

    cout << res;

    return 0;

}