Submission #940827

#	Time	Username	Problem	Language	Result	Execution time	Memory
940827		whatthemomooofun1729	Raisins (IOI09_raisins)	C++14	100 / 100	123 ms	26968 KiB

raisins

#include <iostream>
#include <algorithm>
#include <utility>
#include <vector>
#include <stack>
#include <map>
#include <queue>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <cstring>
#include <cmath>
#include <functional>
#include <cassert>
#include <iomanip>
#include <numeric>
#include <bitset>
#include <sstream>
#include <chrono>
#include <random>

#define ff first
#define ss second
#define ll long long
#define ld long double
#define PB push_back
#define MP make_pair
#define MT make_tuple
#define EB emplace_back
#define PoB pop_back
#define LOG log2
#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define fch(t, v) for (auto t : v)
#define sz(x) int(x.size())
#define rsz resize
#define gp(x) vector<vector<x>>
#define btree vector<pii>
#define vll vector<ll>
#define Max(a, b, c) max(max(a,b),c)
#define fMax(a, b, c, d) max(Max(a, b, c), dp)
#define Min(a, b, c) min(min(a,b),c)
#define Mid(a, b, c) max(min(a, b), min(max(a, b), c))
#define st(a) set<a>
#define gi greater<int>
#define all(x) (x).begin(),(x).end()
#define tri(x) tuple<x,x,x>
#define pil pair<int, long>
#define ull unsigned long long
#define eps 1e-9
//#define debug(x) cout << '>' << #x << ':' << x << endl;

using namespace std;

void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ", "; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? ", " : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
void println() {cerr << ">--------------------<" << endl;}
void printm(vector<vector<int>>& mat) {
    cerr << "matrix: " << endl;
    for (int i = 0; i<(int)mat.size(); i++) {for (int j = 0; j<(int)mat[0].size(); j++) {cerr << mat[i][j] << " ";} cerr << endl;}
}

#ifndef ONLINE_JUDGE
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif

typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;

// templates
template <class T> bool ckmin(T &a, const T &b) {return b<a ? a = b, 1 : 0;}
template <class T> bool ckmax(T &a, const T &b) {return b>a ? a = b, 1 : 0;}
template <class T> using gr = greater<T>;
mt19937_64 rng_ll(chrono::steady_clock::now().time_since_epoch().count());
template <class T> using vc = vector<T>;
template <class T> using p_q = priority_queue<T>;
template <class T> using pqg = priority_queue<T, vc<T>, gr<T>>;
template <class T1, class T2> using pr = pair<T1, T2>;
int rng(int M) {return (int)(rng_ll()%M);}

constexpr int INF = (int)2e9;
constexpr int MOD = 998244353;
constexpr ll LL_INF = (ll)3e18;
constexpr int mod = (int)1e9 + 7;
constexpr ll inverse = 500000004LL; // inverse of 2 modulo 1e9 + 7

void setIO(const string& str) {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    if (str.empty()) return;
    freopen((str + ".in").c_str(), "r", stdin);
    freopen((str + ".out").c_str(), "w", stdout);
}

int N, M;
int grid[51][51], psum[51][51];
int dp[51][51][51][51];

int w(int x1, int y1, int x2, int y2) {
    return psum[x2][y2] - (y1 > 0 ? psum[x2][y1-1] : 0) - (x1 > 0 ? psum[x1-1][y2] : 0) + (y1 > 0 && x1 > 0 ? psum[x1-1][y1-1] : 0);
}

int main() { // TIME YOURSELF !!!
    setIO("");
    cin >> N >> M;
    memset(dp, 0x3f, sizeof(dp));
    for (int i = 0; i < N; ++i) {
        for (int j = 0; j < M; ++j) {
            cin >> grid[i][j];
        }
    }
    for (int i = 0; i < N; ++i) {
        for (int j = 0; j < M; ++j) {
            psum[i][j] = (i > 0 ? psum[i-1][j] : 0) + (j > 0 ? psum[i][j-1] : 0) - (i > 0 && j > 0 ? psum[i-1][j-1] : 0) + grid[i][j];
        }
    }
    for (int i = N-1; i >= 0; --i) {
        for (int j = M-1; j >= 0; --j) {
            for (int k = i; k < N; ++k) {
                for (int l = j; l < M; ++l) {
                    if (k == i && l == j) {
                        dp[i][j][k][l] = 0;
                        continue;
                    }
                    int weight = w(i, j, k, l);
                    for (int m = i; m < k; ++m) {
                        ckmin(dp[i][j][k][l], dp[i][j][m][l] + weight + dp[m+1][j][k][l]);
                    }
                    for (int m = j; m < l; ++m) {
                        ckmin(dp[i][j][k][l], weight + dp[i][j][k][m] + dp[i][m+1][k][l]);
                    }
                }
            }
        }
    }
    cout << dp[0][0][N-1][M-1];
    return 0;
}

// CHECK LONG LONGS, binary search on ans?
// 5000 * 5000 size matrices are kinda big (potential mle)
// Do something, start simpler
// IBM motto: THINK

Compilation message (stderr)

raisins.cpp: In function 'void setIO(const string&)':
raisins.cpp:115:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  115 |     freopen((str + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
raisins.cpp:116:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  116 |     freopen((str + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 100 / 100