Submission #405192

#	Time	Username	Problem	Language	Result	Execution time	Memory
405192		Falcon	Bootfall (IZhO17_bootfall)	C++17	100 / 100	746 ms	3908 KiB

bootfall

#include <bits/stdc++.h>

#ifdef DEBUG
#include "debug.hpp"
#endif

using namespace std;

#define all(c)              (c).begin(), (c).end()
#define rall(c)             (c).rbegin(), (c).rend()
#define traverse(c, it)     for(auto it = (c).begin(); it != (c).end(); ++it)
#define rep(i, N)           for(int i = 0; i < (N); ++i)
#define rrep(i, N)          for(int i = (N) - 1; i >= 0; --i)
#define rep1(i, N)          for(int i = 1; i <= (N); ++i)
#define rep2(i, s, e)       for(int i = (s); i <= (e); ++i)

#ifdef DEBUG
#define debug(x...)         { \
                            ++dbg::depth; \
                            string dbg_vals = dbg::to_string(x); \
                            --dbg::depth; \
                            dbg::fprint(__func__, __LINE__, #x, dbg_vals); \
                            }

#define light_debug(x)      { \
                            dbg::light = true; \
                            dbg::dout << __func__ << ":" << __LINE__; \
                            dbg::dout << "  " << #x << " = " << x << endl; \
                            dbg::light = false; \
                            }

#else
#define debug(x...)         42
#define light_debug(x)      42
#endif


using ll = long long;

template<typename T>
inline T& ckmin(T& a, T b) { return a = a > b ? b : a; }

template<typename T>
inline T& ckmax(T& a, T b) { return a = a < b ? b : a; }


int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int n; cin >> n;
    vector<int> a(n); rep(i, n) cin >> a[i];
    int s{accumulate(all(a), 0)};

    vector<long long> ways(s + 1);
    ways[0] = 1; 

    auto add = [&](int x) {
        rrep(i, int(ways.size()))
            if(i - x >= 0) ways[i] += ways[i - x];
    };

    auto remove = [&](int x) {
        rep(i, int(ways.size()))
            if(i - x >= 0) ways[i] -= ways[i - x];
    };

    rep(i, n) add(a[i]);
    debug(ways);

    if(s % 2 != 0 || ways[s / 2] == 0)
        return cout << 0 << '\n', 0;

    vector<int> c(s + 1);
    vector<bool> b(s + 1);
    rep(i, n) {
        remove(a[i]);
        rep(x, int(ways.size())) {
            if(ways[x] == 0) continue;
            b[abs(s - a[i] - 2 * x)] = true;
        }

        rep(x, int(c.size()))
            if(b[x]) ++c[x], b[x] = false; 
        debug(i, ways);
        add(a[i]);
    }

    cout <<  count_if(all(c), [&](int x) { return x == n; }) << '\n';

    rep(i, int(c.size())) if(c[i] == n) cout << i << ' ';
    cout << '\n';
    
    
    #ifdef DEBUG
    dbg::dout << "\nExecution time: "
              << clock() * 1000 / CLOCKS_PER_SEC 
              << "ms" << endl;
    #endif
    return 0;
}

Compilation message (stderr)

bootfall.cpp: In function 'int main()':
bootfall.cpp:33:29: warning: statement has no effect [-Wunused-value]
   33 | #define debug(x...)         42
      |                             ^~
bootfall.cpp:69:5: note: in expansion of macro 'debug'
   69 |     debug(ways);
      |     ^~~~~
bootfall.cpp:33:29: warning: statement has no effect [-Wunused-value]
   33 | #define debug(x...)         42
      |                             ^~
bootfall.cpp:85:9: note: in expansion of macro 'debug'
   85 |         debug(i, ways);
      |         ^~~~~

• Subtask 1: 6 / 6
• Subtask 2: 7 / 7
• Subtask 3: 15 / 15
• Subtask 4: 16 / 16
• Subtask 5: 21 / 21
• Subtask 6: 35 / 35