Submission #229745

#	Time	Username	Problem	Language	Result	Execution time	Memory
229745		Coder	T-Covering (eJOI19_covering)	C++14	25 / 100	129 ms	16712 KiB

covering

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
#define SZ(x) (int)(x.size())
#define F0(i,n) for(int i=0;i<n;i++)
#define F1(i,n) for(int i=1;i<=n;i++)
#define CL(a,x) memset(x, a, sizeof(x));
#define PR(x) cerr << #x << "=" << (x) << endl;
const int MOD = 1000000007;
const double pi = atan(1.0)*4.0;
const double eps = 1e-8;
const int N = 1000001;
int i, j, k, m, n;
int a[N];

int b[N], d[N], c[N];
ll ans;
const int DX[]={-1,0,1,0,0};
const int DY[]={0,1,0,-1,0};

void nosol() {
    cout << "No" << endl;
    exit(0);
}

bool Empty(int x, int y) {
    if (x < 0 || x >= m || y < 0 || y >= n) return 0;
    return !c[x*n + y];
}

int GetA(int x, int y) {
    return a[x*n + y];
}

void Fill(int x, int y) {
    c[x*n + y] = 1;
    ans += GetA(x, y);
}

int main() {
    //freopen("x.in", "r", stdin);
    cin >> m >> n;
    F0(i, m * n) scanf("%d", &a[i]);
    cin >> k;
    while (k--) {
        scanf("%d%d", &i, &j);
        b[i*n+j] = 1;
    }
    // find pairs
    F0(i, m) F0(j, n) if (b[i*n + j]) {
        for (int dx = -1; dx <= 1; dx++) {
            for (int dy = -1; dy <= 1; dy++) if (dx || dy) {
                int i2 = i + dx, j2 = j + dy;
                if (i2 < 0 || i2 >= m || j2 < 0 || j2 >= n || !b[i2*n + j2]) continue;
                if (d[i*n + j] && d[i2*n + j2]) continue;
                if (d[i*n + j] || d[i2*n + j2]) nosol();
                d[i*n + j] = 1;
                d[i2*n + j2] = 1;
                F0(k, 5) if (!Empty(i + DX[k], j + DY[k])) nosol();
                F0(k, 5) if (!Empty(i2 + DX[k], j2 + DY[k])) nosol();
                F0(k, 5) if (Empty(i + DX[k], j + DY[k])) Fill(i + DX[k], j + DY[k]);
                F0(k, 5) if (Empty(i2 + DX[k], j2 + DY[k])) Fill(i2 + DX[k], j2 + DY[k]);
            }
        }
    }

    F0(i, m) F0(j, n) if (b[i*n + j] && !d[i*n + j]) {
        if (!Empty(i, j)) nosol();
        int bsum = -1;
        int bk = -1;
        F0(k, 4) {
            int good = 1, sum = 0;
            F0(dir, 4) if (dir != k) {
                if (!Empty(i + DX[dir], j + DY[dir])) {
                    good = 0;
                    break;
                } else {
                    sum += GetA(i + DX[dir], j + DY[dir]);
                }
            }
            if (sum > bsum) {
                bsum = sum;
                bk = k;
            }
        }
        if (bk == -1) nosol();
        d[i*n + j] = 1;
        F0(dir, 5) if (dir != bk) Fill(i + DX[dir], j + DY[dir]);
    }

    cout << ans << endl;

    return 0;
}

Compilation message (stderr)

covering.cpp: In function 'int main()':
covering.cpp:73:17: warning: variable 'good' set but not used [-Wunused-but-set-variable]
             int good = 1, sum = 0;
                 ^~~~
covering.cpp:44:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     F0(i, m * n) scanf("%d", &a[i]);
                  ~~~~~^~~~~~~~~~~~~
covering.cpp:47:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d", &i, &j);
         ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 15
• Subtask 6: 0 / 20
• Subtask 7: 0 / 30