#include <iostream>#include <algorithm>#define FOR(i,s,p) for(int i=(s);i<=(p);i++)using namespace std;void expand(char i, bool b[]){b[0] = i & 1; i >>= 1;b[1] = i & 1; i >>= 1;b[2] = i & 1;}// 这里使用了二项式中的思想, 3个k char sign(bool b[]){return (b[0] + b[1] + b[2]) % 2 == 1 ? -1 : 1;}const int maxn = 30;const long long INF = 1LL << 60;long long S[maxn][maxn][maxn];long long sum(int x1, int x2, int y1, int y2, int z1, int z2){int dx = x2 – x1 + 1, dy = y2 – y1 + 1, dz = z2 – z1 + 1;long long s = 0;bool b[3];for (int i = 0; i < 8; i++){expand(i, b);s += (S[x1 + dx*b[0]][y1 + dy*b[1]][z1 + dz*b[2]])*sign(b);}return s;}int main(){int T;cin >> T;while (T–){int a, b, c;bool bb[3];cin >> a >> b >> c;memset(S, 0, sizeof(S));FOR(x, 1, a)FOR(y, 1, b)FOR(z, 1, c) cin >> S[x][y][z];FOR(x, 1, a)FOR(y, 1, b)FOR(z, 1, c) for (char i = 1; i <= 7;i++) {expand(i, bb);S[x][y][z] += S[x – bb[0]][y – bb[1]][z – bb[2]] * sign(bb);;}long long ans = -INF;long long M=0;FOR(x1, 1, a)FOR(x2, x1, a)FOR(y1, 1, b)FOR(y2, y1, b)FOR(z, 1, c){long long s = sum(x1, x2, y1, y2, 1, z);ans = max(s-M , ans);M = min(M, s);}cout << ans;if (T) cout << '\n';}return 0;}
，敢于奋斗的人，心中不怕困难。
