Submission #298667

#	Time	Username	Problem	Language	Result	Execution time	Memory
298667		jainbot27	The Kingdom of JOIOI (JOI17_joioi)	C++17	100 / 100	639 ms	54904 KiB

joioi

#pragma GCC optimize("Ofast")
#pragma GCC target("sse4,avx,avx2,fma")
#include <bits/stdc++.h>
using namespace std;


#define f first
#define s second
#define pb push_back
#define mp make_pair
#define ts to_string
#define ub upper_bound
#define lb lower_bound
#define ar array
#define all(x) x.begin(), x.end()
#define siz(x) (int)x.size()
#define FOR(x, y, z) for(int x = (y); x < (z); x++)
#define ROF(x, y, z) for(int x = (y-1); x >= (z); x--)
#define F0R(x, z) FOR(x, 0, z)
#define R0F(x, z) ROF(x, z, 0)
#define trav(x, y) for(auto&x:y)

const string nl = "\n";
using ll = int64_t;
using vi = vector<int>;
using vl = vector<ll>;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using str = string;
using vpii = vector<pii>;
using vpll = vector<pll>;


template<class T> inline bool ckmin(T&a, T b) {return b < a ? a = b, 1 : 0;}
template<class T> inline bool ckmax(T&a, T b) {return b > a ? a = b, 1 : 0;}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
void usaco(string x=""){
    ios_base::sync_with_stdio(0); cin.tie(0); x=x;
#ifndef D
    if(siz(x)){
        freopen((x+".in").c_str(), "r", stdin);
        freopen((x+".out").c_str(), "w", stdout);
    }
#endif
}


str ts(char c) { return str(1,c); }
str ts(bool b) { return b ? "true" : "false"; }
str ts(const char* s) { return (str)s; }
str ts(str s) { return s; }
template<class A> str ts(complex<A> c) { 
    stringstream ss; ss << c; return ss.str(); }
str ts(vector<bool> v) { 
    str res = "{"; for(int i = 0;i < (int)v.size(); i++) res += char('0'+v[i]);
    res += "}"; return res; }
template<size_t SZ> str ts(bitset<SZ> b) {
    str res = ""; for(int i = 0; i < b.size(); i++) res += char('0'+b[i]);
    return res; }
template<class A, class B> str ts(pair<A,B> p);
template<class T> str ts(T v) { 
    bool fst = 1; str res = "{";
    for (const auto& x: v) {
        if (!fst) res += ", ";
        fst = 0; res += ts(x);
    }
    res += "}"; return res;
}
template<class A, class B> str ts(pair<A,B> p) {
    return "("+ts(p.f)+", "+ts(p.s)+")"; }
void DBG() { cerr << "]" << endl; }
template<class H, class... T> void DBG(H h, T... t) {
    cerr << ts(h); if (sizeof...(t)) cerr << ", ";
    DBG(t...); }


#ifdef D 
#define dbg(...) cerr << "LINE(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif

int h, w, a[2001][2001], mx, mn = 1e9 + 1;
void fr(){
    F0R(i, h){
        F0R(j, w/2){
            assert(j <= w-j-1);
            swap(a[i][j], a[i][w-j-1]);
        }
    }
}
void fc(){
    F0R(i, h/2){
        F0R(j, w){
            assert(i <= h-i-1);
            swap(a[i][j], a[h-i-1][j]);
        }
    }
}
bool works(int dif){
    dbg(dif);
    int u = w;
    F0R(i, h){
        int j=0;
        for(; j < u; j++){
            if(mn + dif < a[i][j])
                break;
        }
        dbg(j);
        u = j;
        for(j = u; j < w; j++)
            if(mx - dif > a[i][j])
                return 0;
    }
    dbg("YES");
    return 1;
}
signed main(){
    usaco("");
    cin >> h >> w;
    F0R(i, h) F0R(j, w) cin >> a[i][j], ckmax(mx, a[i][j]), ckmin(mn, a[i][j]);
    dbg(mn, mx);
    int l = 0, r = mx, res = 2e9;
    while(l <= r){
        int m = (l + r)/2;
        if(works(m)){
            r = m - 1;
        }
        else{
            l = m + 1;
        }
    }
    ckmin(res, l);
    fc();
    l = 0,r =mx;
    while(l <= r){
        int m = (l + r)/2;
        if(works(m)){
            r = m - 1;
        }
        else{
            l = m + 1;
        }
    }
    ckmin(res, l);
    fc(); 
    fr();
    l = 0,r =mx;
    while(l <= r){
        int m = (l + r)/2;
        if(works(m)){
            r = m - 1;
        }
        else{
            l = m + 1;
        }
    }
    ckmin(res, l);
    l = 0,r =mx;
    fc();
    while(l <= r){
        int m = (l + r)/2;
        if(works(m)){
            r = m - 1;
        }
        else{
            l = m + 1;
        }
    }
    ckmin(res, l);
    cout << res << nl;

}
/*
2 2
2 3
4 5
*/
/*
 * Stuff I should try:
 * Is it Monotonic? -> Binary Search
 * Is N small? -> Bitsets or other exponential
 * Edge Cases? Look Carefully 
 * Can't figure anything out? Brute Force and see patterns
 * Try to prove greedies
 * Prefix Sums, Amortization, DP, Data Structures
*/

Compilation message (stderr)

joioi.cpp: In function 'bool works(int)':
joioi.cpp:80:18: warning: statement has no effect [-Wunused-value]
   80 | #define dbg(...) 0
      |                  ^
joioi.cpp:101:5: note: in expansion of macro 'dbg'
  101 |     dbg(dif);
      |     ^~~
joioi.cpp:80:18: warning: statement has no effect [-Wunused-value]
   80 | #define dbg(...) 0
      |                  ^
joioi.cpp:109:9: note: in expansion of macro 'dbg'
  109 |         dbg(j);
      |         ^~~
joioi.cpp:80:18: warning: statement has no effect [-Wunused-value]
   80 | #define dbg(...) 0
      |                  ^
joioi.cpp:115:5: note: in expansion of macro 'dbg'
  115 |     dbg("YES");
      |     ^~~
joioi.cpp: In function 'int main()':
joioi.cpp:80:18: warning: statement has no effect [-Wunused-value]
   80 | #define dbg(...) 0
      |                  ^
joioi.cpp:122:5: note: in expansion of macro 'dbg'
  122 |     dbg(mn, mx);
      |     ^~~
joioi.cpp: In function 'void usaco(std::string)':
joioi.cpp:41:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   41 |         freopen((x+".in").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
joioi.cpp:42:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   42 |         freopen((x+".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 45 / 45
• Subtask 3: 40 / 40