86 lines
2.3 KiB
C++
86 lines
2.3 KiB
C++
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#include<bits/stdc++.h>
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using namespace std;
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using ll = int64_t;
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constexpr int MAXN = 42;
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int n, m;
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ll a[MAXN][MAXN];
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ll x[MAXN][MAXN];
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int main() {
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cin >> n >> m;
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ll cnt1 = 0, sum1 = 0, cnt2 = 0, sum2 = 0;
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for(int i = 0; i < n; ++i) {
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for(int j = 0; j < m; ++j) {
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cin >> a[i][j];
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if ((i + j) & 1) {
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++cnt1;
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sum1 += a[i][j];
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} else {
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++cnt2;
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sum2 += a[i][j];
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}
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}
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}
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ll l = 0, r = LLONG_MAX / (MAXN * MAXN);
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if ((n * m) & 1) {
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l = (sum1 - sum2) / (cnt1 - cnt2);
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r = l + 1;
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}
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ll res = LLONG_MAX;
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int o = 0;
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while(l < r) {
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memset(x, 0, sizeof(x));
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ll mid = l + r >> 1;
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cerr << mid << endl;
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int f = 1;
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ll cnt = 0;
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for(int i = 0; i < n; ++i) {
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for (int j = 0; j < m; ++j) {
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ll available = mid - a[i][j] - x[i][j];
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if (available < 0) {
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f = 0;
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goto finish;
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}
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if (i + 1 == n) {
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if (j + 1 == m) {
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continue;
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}
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ll lo = min(available, mid - a[i][j+1] - x[i][j+1]);
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x[i][j+1] += lo;
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if (available != lo) {
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f = 0;
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goto finish;
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}
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} else {
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if (j + 1 == m) {
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ll lo = min(available, mid - a[i+1][j] - x[i+1][j]);
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x[i+1][j] += lo;
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if (available != lo) {
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f = 0;
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goto finish;
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}
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} else {
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ll lo = min(available, mid - a[i][j+1] - x[i][j+1]);
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x[i][j+1] += lo;
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x[i+1][j] += available - lo;
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}
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}
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cnt += 2 * available;
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}
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}
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finish:
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if(f) {
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r = mid;
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o = 1;
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res = min(res, cnt);
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} else {
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l = mid + 1;
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}
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}
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if (o) {
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cout << res;
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} else {
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cout << -1;
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}
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}
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