Submission #1261173

#	Time	Username	Problem	Language	Result	Execution time	Memory
1261173		Pablo_No	Bomb (IZhO17_bomb)	C++20	67 / 100	178 ms	61812 KiB

bomb

#include<bits/stdc++.h>
using namespace std;
const int inf = 1000000000;
char c1[2505][2505],c2[2505][2505];
int n,m,l,r,bolo;
int lf[2505][2505],rg[2505][ 2505],zr[2505];
pair<int, int> ans;

int main(){
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;++i) scanf("%s", &c1[i][1]);
    for(int i=0;i<2505;++i) zr[i] = inf;

    for(int i=0;i<1;++i) {
        memset((lf), 0, sizeof(lf));
        memset((rg), 0, sizeof(rg));
        for(int i=1;i<=n;++i){
            for(int j=1;j<=m;++j)
                if(c1[i][j] == '1') lf[i][j] = lf[i][j-1] + 1;
            for(int j=m;j>=1;--j)
                if(c1[i][j] == '1') rg[i][j] = rg[i][j+1] + 1;
            for(int j=1;j<=m;++j)
                if(c1[i][j] == '1' && c1[i][j+1] != '1') zr[1] = min(zr[1], lf[i][j]);
        }

        for(int j=1;j<=m;++j)
            for(int i=0;i<=n+1;++i)
                if(c1[i][j] == '1') {
                    l = min(l, lf[i][j]);  r = min(r, rg[i][j]);
                    zr[i - bolo] = min(zr[i - bolo], l + r - 1);
                } else {
                    if(i && bolo != i-1) zr[i - bolo] = 0;
                    l = inf; r = inf;  bolo = i;
                }
        for(int i=1;i<=n;++i)
            for(int j=1;j<=m;++j)
                c2[i][j] = c1[n+1-i][j];
        for(int i=1;i<=n;++i)
            for(int j=1;j<=m;++j)
                c1[i][j] = c2[i][j];
    }
    int b = inf;

    for(int a=1;a<=2504;++a) {
        b = min(b, zr[a]);
        ans = max(ans, {a*b, b});
    }

    cout << ans.first << endl;
}

Compilation message (stderr)

bomb.cpp: In function 'int main()':
bomb.cpp:10:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 |     scanf("%d%d",&n,&m);
      |     ~~~~~^~~~~~~~~~~~~~
bomb.cpp:11:32: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 |     for(int i=1;i<=n;++i) scanf("%s", &c1[i][1]);
      |                           ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 67 / 100