Editorial for Cắt bảng
Remember to use this editorial only when stuck, and not to copy-paste code from it. Please be respectful to the problem author and editorialist.
Submitting an official solution before solving the problem yourself is a bannable offence.
Submitting an official solution before solving the problem yourself is a bannable offence.
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> #include <cstring> using namespace std; int f[1 << 16], a[4][4], m, n; int dp(int mask) { if (!mask) return 0; int &res = f[mask]; if (res >= 0) return res; res = 0; for (int i = 0; i < m; i++) for (int j = 0; j < n; j++) if (mask >> (i * n + j) & 1) { // horizontal int x = a[i][j], usedMask = 1 << (i * n + j); res = max(res, dp(mask - usedMask) + x); for (int k = j + 1; k < n; k++) if (mask >> (i * n + k) & 1) { x = x * 10 + a[i][k]; usedMask += 1 << (i * n + k); res = max(res, dp(mask - usedMask) + x); } else break; // vertical x = a[i][j]; usedMask = 1 << (i * n + j); for (int k = i + 1; k < m; k++) if (mask >> (k * n + j) & 1) { x = x * 10 + a[k][j]; usedMask += 1 << (k * n + j); res = max(res, dp(mask - usedMask) + x); } } return res; } int main() { memset(f, -1, sizeof(f)); cin >> m >> n; for (int i = 0; i < m; i++) for (int j = 0; j < n; j++) cin >> a[i][j]; cout << dp((1 << (m * n)) - 1) << endl; }
Code mẫu của happyboy99x
#include<cstdio> int temp, res, a[5][5], used[5][5], m, n, step = 0; void backtrack(int i, int j) { if(j == n) { if(i == m-1) { if(temp > res) res = temp; } else backtrack(i+1, 0); } else if(used[i][j]) backtrack(i, j+1); else { ++step; used[i][j] = step; temp += a[i][j]; backtrack(i, j+1); temp -= a[i][j]; int x = a[i][j]; for(int c = j + 1; ; ++c) if(used[i][c]) { for(int y = j + 1; y < c; ++y) used[i][y] = 0; break; } else { x = x * 10 + a[i][c]; used[i][c] = step; temp += x; backtrack(i, c+1); temp -= x; } x = a[i][j]; for(int r = i + 1; ; ++r) if(used[r][j]) { for(int x = i + 1; x < r; ++x) used[x][j] = 0; break; } else { x = x * 10 + a[r][j]; used[r][j] = step; temp += x; backtrack(i, j+1); temp -= x; } used[i][j] = 0; --step; } } int main() { scanf("%d%d", &m, &n); for(int i = 0; i < m; ++i) for(int j = 0; j < n; ++j) scanf("%d", &a[i][j]); for(int j = 0; j <= n; ++j) used[m][j] = 1; for(int i = 0; i <= m; ++i) used[i][n] = 1; backtrack(0, 0); printf("%d\n", res); return 0; }
Code mẫu của ladpro98
program c11cut; uses math; const fi=''; cx:array[1..9] of longint = (0,0,0,0,1,2,3,4,0); cy:array[1..9] of longint = (1,2,3,4,0,0,0,0,0); var a:array[1..4,1..4] of longint; check:array[1..4,1..4] of boolean; m,n,res:longint; procedure input; var inp:text; i,j:longint; begin assign(inp,fi); reset(inp); readln(inp,m,n); for i:=1 to m do begin for j:=1 to n do read(inp,a[i,j]); readln(inp); end; close(inp); end; function sum(i,j,x,y:longint):longint; var p,t:longint; begin t:=0; if i=x then for p:=j to y do t:=10*t+a[i,p] else for p:=i to x do t:=10*t+a[p,j]; exit(t); end; procedure like(i,j,x,y:longint); var p,q:longint; begin for p:=i to x do for q:=j to y do check[p,q]:=true; end; procedure unlike(i,j,x,y:longint); var p,q:longint; begin for p:=i to x do for q:=j to y do check[p,q]:=false; end; function ok(i,j,x,y:longint):boolean; var p,q:longint; begin for p:=i to x do for q:=j to y do if check[p,q] then exit(false); exit(true); end; procedure back(i,j,s:longint); var k,x,y:longint; begin if i>m then begin res:=max(res,s); exit; end; if check[i,j] then begin if j<n then back(i,j+1,s) else back(i+1,1,s); exit; end; for k:=1 to 9 do begin x:=i+cx[k]; y:=j+cy[k]; if (x<=m) and (y<=n) then if ok(i,j,x,y) then begin like(i,j,x,y); if j<n then back(i,j+1,s+sum(i,j,x,y)) else back(i+1,1,s+sum(i,j,x,y)); unlike(i,j,x,y); end; end; end; begin input; back(1,1,0); write(res); end.
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 f[10][10][10][10]; int m, n, a[10][10]; int row(int i, int l, int r) { int res = 0; FOR(j,l,r) res = res * 10 + a[i][j]; return res; } int col(int j, int l, int r) { int res = 0; FOR(i,l,r) res = res * 10 + a[i][j]; return res; } int get(int u, int v, int x, int y) { if (f[u][v][x][y] >= 0) return f[u][v][x][y]; if (u == x && v == y) return a[u][v]; int res = 0; if (u < x) { res = max(res, row(u, v, y) + get(u+1, v, x, y)); res = max(res, row(x, v, y) + get(u, v, x-1, y)); } else res = max(res, row(u, v, y)); if (v < y) { res = max(res, col(v, u, x) + get(u, v+1, x, y)); res = max(res, col(y, u, x) + get(u, v, x, y-1)); } else res = max(res, col(v, u, x)); return f[u][v][x][y] = res; } int main() { scanf("%d%d", &m, &n); FOR(i,1,m) FOR(j,1,n) scanf("%d", &a[i][j]); memset(f, -1, sizeof f); cout << get(1, 1, m, n) << 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> #include <cassert> 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-13; const int dr[] = {0, +1, 0, -1}; const int dc[] = {+1, 0, -1, 0}; const int inf = (int)1e9 + 5; const ll linf = (ll)1e16 + 5; const ll mod = (ll)1e9 + 7; int n, m, a[5][5], f[5][5][5][5]; int cal(int r1, int c1, int r2, int c2){ int res = 0; if(r1 == r2){ For(i, c1, c2) res = res * 10 + a[r1][i]; } else{ For(i, r1, r2) res = res * 10 + a[i][c1]; } return res; } int main(){ // freopen("in.txt", "r", stdin); cin >> n >> m; For(i, 1, n) For(j, 1, m) cin >> a[i][j]; For(r, 0, n - 1) For(c, 0, m - 1) For(i, 1, n - r) For(j, 1, m - c){ if(r == 0 || c == 0) { f[i][j][i + r][j + c] = cal(i, j, i + r, j + c); continue; } f[i][j][i + r][j + c] = 0; f[i][j][i + r][j + c] = max(f[i][j][i + r][j + c], cal(i, j, i, j + c) + f[i + 1][j][i + r][j + c]); f[i][j][i + r][j + c] = max(f[i][j][i + r][j + c], cal(i, j, i + r, j) + f[i][j + 1][i + r][j + c]); f[i][j][i + r][j + c] = max(f[i][j][i + r][j + c], cal(i + r, j, i + r, j + c) + f[i][j][i + r - 1][j + c]); f[i][j][i + r][j + c] = max(f[i][j][i + r][j + c], cal(i, j + c, i + r, j + c) + f[i][j][i + r][j + c - 1]); } cout << f[1][1][n][m]; return 0; }
Code mẫu của skyvn97
#include<stdio.h> #define MAX 17 int a[MAX][MAX]; int x[MAX][MAX]; long best; int m,n; void update(void) { int i,j,k; long sum,val; bool saw[MAX][MAX]; for (i=1;i<=m;i=i+1) for (j=1;j<=n;j=j+1) saw[i][j]=false; sum=0; for (i=1;i<=m;i=i+1) for (j=1;j<=n;j=j+1) { if (saw[i][j]) continue; val=a[i][j]; if (x[i][j]==1) { for (k=j+1;k<=n;k=k+1) { if (x[i][k]!=1) break; else { val=val*10+a[i][k]; saw[i][k]=true; } } } if (x[i][j]==2) { for (k=i+1;k<=m;k=k+1) { if (x[k][j]!=2) break; else { val=val*10+a[k][j]; saw[k][j]=true; } } } sum=sum+val; saw[i][j]=true; } if (sum>best) best=sum; } void btrk(int r,int c) { int i; for (i=1;i<=2;i=i+1) { x[r][c]=i; if (c==n) { if (r==m) update(); else btrk(r+1,1); } else btrk(r,c+1); } } void init(void) { int i,j; scanf("%d",&m); scanf("%d",&n); for (i=1;i<=m;i=i+1) for (j=1;j<=n;j=j+1) scanf("%d",&a[i][j]); best=0; } int main(void) { init(); btrk(1,1); printf("%ld",best); }
Comments