NDCCARD - Các lá bài Blackjack
Tác giả: RR
Ngôn ngữ: C++
#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;
const int BUFSIZE = (1<<12) + 17;
char BUF[BUFSIZE+1], *inp=BUF;
#define GETCHAR(INP) { \
if(!*inp && !REACHEOF) { \
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, m;
int bit[500111];
int a[10111];
#define _(x) ((x) & (-(x)))
int update(int u, int k) {
while (u <= m) {
bit[u] = max(bit[u], k);
u += _(u);
}
}
int get(int u) {
int res = -1;
while (u > 0) {
res = max(res, bit[u]);
u -= _(u);
}
return res;
}
int main() {
while (scanf("%d%d", &n, &m) == 2) {
memset(bit, 0, sizeof bit);
FOR(i,1,n) scanf("%d", &a[i]);
sort(a+1, a+n+1);
int res = 0;
FOR(i,1,n) {
if (a[i] >= m) break;
int sum, t;
FOR(j,i+1,n) {
sum = a[i] + a[j];
if (sum >= m) break;
t = get(m - sum);
if (t >= 0) {
res = max(res, sum + t);
}
}
update(a[i], a[i]);
}
printf("%d\n", res);
}
return 0;
}