Submission #2698911

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;

#define NDEBUG
#ifdef DEBUG
#include "../cout11.h"
#undef NDEBUG
#endif
#include <cassert>

typedef long long ll;
typedef long double Double;
typedef unsigned long long ull;
typedef pair<int,int> ii;
typedef pair<ll,ll> llll;
typedef pair<double,double> dd;

typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef vector<ii> vii;
typedef vector<vector<ii>> vvii;
typedef vector<ll> vll;
typedef vector<vll> vvll;
typedef vector<string> vs;
typedef vector<double> vd;
typedef vector<long double> vD;

#define sz(a)  int((a).size())
#define pb  push_back
#define FOR(var,from,to) for(int var=(from);var<=(to);++var)
#define rep(var,n)  for(int var=0;var<(n);++var)
#define rep1(var,n)  for(int var=1;var<=(n);++var)
#define repC2(vari,varj,n)  for(int vari=0;vari<(n)-1;++vari)for(int varj=vari+1;varj<(n);++varj)
#define ALL(c)  (c).begin(),(c).end()
#define RALL(c)  (c).rbegin(),(c).rend()
#define tr(i,c)  for(auto i=(c).begin(); i!=(c).end(); ++i)
#define found(s,e)  ((s).find(e)!=(s).end())
#define mset(arr,val)  memset(arr,val,sizeof(arr))
#define mid(x,y) ((x)+((y)-(x))/2)
#define IN(x,a,b) ((a)<=(x)&&(x)<=(b))

ll gcd(ll a, ll b) { while(a) swap(a, b%=a); return b; }

const ll MOD=1000000007LL;

ll ADD(ll x, ll y) { return (x+y) % MOD; }
ll SUB(ll x, ll y) { return (x-y+MOD) % MOD; }
ll MUL(ll x, ll y) { return x*y % MOD; }
ll POW(ll x, ll e) { ll v=1; for(; e; x=MUL(x,x), e>>=1) if (e&1) v = MUL(v,x); return v; }
ll DIV(ll x, ll y) { /*assert(y%MOD!=0);*/ return MUL(x, POW(y, MOD-2)); }
// ll comb(ll n, ll k) { ll v=1; for(ll i=1; i<=k; i++) v = DIV(MUL(v, n-i+1),i); return v; }
//

#define INTSPACE 12
char _buf[INTSPACE*1000000 + 3];

int loadint() {
    if (fgets(_buf, INTSPACE+3, stdin)==NULL) return 0;
    return atoi(_buf);
}

int loadvec(vector<int>& v, int N=-1) {
    if (N == -1) {
        N = loadint();
        if (N==0) return 0;
    }
    int bufsize = INTSPACE*N + 3;
    if (fgets(_buf, bufsize, stdin)==NULL) return 0;
    v.resize(N);

    int i=0;
    bool last = false;
    for (char *p=&_buf[0]; ;) {
        char *q = p;
        while (*q > ' ') ++q;
        if (*q == 0x0D || *q == 0x0A) last = true;
        *q = 0;
        v[i++] = atoi(p);
        if (last || i == N) break;
        p = q+1;
    }
    // assert(i <= N);
    return i;
}
void read_cr() {
    fgets(_buf, 256, stdin);
}

ll solve(int N,int K,vi& a) {
    int cap = K*2;
    rep(i,N) a[i] = min(cap, a[i]);
    cap = min(K + *max_element(ALL(a)), cap);

    vvi pre(N+1, vi(1+cap, 0)),
         post(N+1, vi(1+cap, 0));
    vvi pre_(N+1, vi());
    vvi post_(N+1, vi());

    pre[0][0] = 1;
    pre_[0].pb(0);
    for (int i=0; i<N; ++i){
        int d = a[i];
        rep(j,1+cap){
            if (!pre[i][j]) continue;
            pre[i+1][j] |= 1;
            if (j+d <= cap) pre[i+1][j+d] |= 1;
        }
        rep(j,1+cap) {
            if (pre[i+1][j]) pre_[i+1].pb(j);
        }
        // cerr << pre_[i+1] << endl;
    }

    post[0][0] = 1;
    post_[0].pb(0);
    for (int i=0; i<N; ++i){
        int d = a[N-1-i];
        rep(j,1+cap){
            if (!post[i][j]) continue;
            post[i+1][j] |= 1;
            if (j+d <= cap) post[i+1][j+d] |= 1;
        }
        rep(j,1+cap) {
            if (post[i+1][j]) post_[i+1].pb(j);
        }
        // cerr << post_[i+1] << endl;
    }

    int ans = 0;
    for (int i=0; i<N; ++i) {
        if (a[i] >= K) {
            // needed = true;
            continue;
        }
        bool needed = false;
#ifdef DEBUG
        cerr << a[i] << pre_[i] << post_[N-1-i] << endl;
        fprintf(stderr, " looking for [%d-%d, %d)\n", K,a[i],K);
#endif
        for (int p : pre_[i]){
            // [k-ai, k) を探してて
            // pを引くから
            // [k-p-ai, k-p)
            auto it = lower_bound(ALL(post_[N-1-i]), K-p-a[i]);
            auto jt = lower_bound(ALL(post_[N-1-i]), K-p);
            if (it != jt) { needed = true; break; }
        }
        if (!needed) ++ans;
    }

    return ans;
}

int main() {
    int N,K; cin >> N >> K;
    read_cr();
    vi a(N);
    loadvec(a,N);
    cout << solve(N,K,a) << endl;
    // cout << (solve(N,a) ? "Yes":"No") << endl;
    return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘void read_cr()’:
./Main.cpp:86:28: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result]
     fgets(_buf, 256, stdin);
                            ^

Judge Result