Submission #537052

#	Time	Username	Problem	Language	Result	Execution time	Memory
537052		qwerasdfzxcl	The Kingdom of JOIOI (JOI17_joioi)	C++14	0 / 100	1 ms	340 KiB

joioi

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
int n, m, a[2020][2020], tmp[2020][2020], d[2020];

bool solve(int val, int x, int y){
    int mn = a[x][y];
    for (int i=1;i<=n;i++){
        for (d[i]=0;d[i]<=d[i-1];d[i]++){
            if (d[i]==m || a[i][d[i]+1] - mn > val) break;
        }
    }
    if (d[x] < y) return 0;

    int mx = 0;
    mn = 1e9;
    for (int i=1;i<=n;i++){
        for (int j=d[i]+1;j<=m;j++){
            mn = min(mn, a[i][j]);
            mx = max(mx, a[i][j]);
        }
    }
    return mx - mn <= val;
}

int getans(int x, int y){
    int l = 0, r = 1e9, ret = 1e9;
    while(l<=r){
        int m = (l+r)>>1;
        if (solve(m, x, y)) ret = m, r = m-1;
        else l = m+1;
    }
    //printf("YES: %d\n", ret);
    return ret;
}

void flipx(int &x, int &y){
    x = n+1-x;
    for (int i=1;i<=n;i++){
        for (int j=1;j<=m;j++){
            tmp[n+1-i][j] = a[i][j];
        }
    }

    for (int i=1;i<=n;i++){
        for (int j=1;j<=m;j++){
            a[i][j] = tmp[i][j];
        }
    }
}

void flipy(int &x, int &y){
    y = m+1-y;
    for (int i=1;i<=n;i++){
        for (int j=1;j<=m;j++){
            tmp[i][m+1-j] = a[i][j];
        }
    }

    for (int i=1;i<=n;i++){
        for (int j=1;j<=m;j++){
            a[i][j] = tmp[i][j];
        }
    }
}

int main(){
    scanf("%d %d", &n, &m);
    d[0] = m;

    int mn = 2e9, x, y;
    for (int i=1;i<=n;i++){
        for (int j=1;j<=m;j++){
            scanf("%d", a[i]+j);
            if (mn > a[i][j]){
                mn = a[i][j];
                x = i, y = j;
            }
        }
    }

    int ans = getans(x, y); flipx(x, y);
    ans = min(ans, getans(x, y)); flipy(x, y);
    ans = min(ans, getans(x, y)); flipx(x, y);
    ans = min(ans, getans(x, y));

    printf("%d\n", ans);

    return 0;
}

Compilation message (stderr)

joioi.cpp: In function 'int main()':
joioi.cpp:69:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   69 |     scanf("%d %d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~~
joioi.cpp:75:18: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   75 |             scanf("%d", a[i]+j);
      |             ~~~~~^~~~~~~~~~~~~~

• Subtask 1: 0 / 15
• Subtask 2: 0 / 45
• Subtask 3: 0 / 40