题目
https://icpcarchive.ecs.baylor.edu/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=996
题意
被射击掉了一些列的魔方。组成模仿的每个方块的六个面颜色相同。给六个面的视图,求魔方最多还剩下多少个小块。
魔方最多十阶。
思路
关键在于将视图的坐标(加上视图深度)映射为三维坐标系内的坐标,之后就可以不断删除会造成矛盾的暴露在表面的方块,直到没有方块或者没有矛盾为止。
感想
1. 注意<写成了>=
2. 忘记了检测当前方块是否已经删除过了。
3. 忘了memset
4. 视图的映射有价值,不过需要注意坐标系建立不同
代码
Runtime: 0.006
#include <algorithm>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <queue>
#include <tuple>
#include <cassert> using namespace std;
#define LOCAL_DEBUG
const int MAXN = ; int n;
bool del[MAXN][MAXN][MAXN];
char color[MAXN][MAXN][MAXN];
char fc[][MAXN][MAXN];
int deep[][MAXN][MAXN];
int facec[];
int polarc[]; char statusDescribe[][] = {
"YXZ",
"ZXy",
"yXz",
"zXY",
"YZx",
"YzX"
}; int getAns() {
int ans = ;
for (int i = ; i < n; i++) {
for (int j = ; j < n; j++) {
for (int k = ; k < n; k++) {
if (!del[i][j][k])ans++;
}
}
}
return ans;
} void face2polar(int fid, int facec[], int polarc[]) {
for (int i = ; i < ; i++) {
char sta = statusDescribe[fid][i];
if (sta >= 'X' && sta <= 'Z') {
polarc[i] = facec[sta - 'X'];
}
else {
polarc[i] = n - - facec[sta - 'x'];
}
}
} void polar2face(int fid, int facec[], int polarc[]) {
for (int i = ; i < ; i++) {
char sta = statusDescribe[fid][i];
if (sta >= 'X' && sta <= 'Z') {
facec[sta - 'X'] = polarc[i];
}
else {
facec[sta - 'x'] = n - - polarc[i];
}
}
} int main() {
#ifdef LOCAL_DEBUG
freopen("input.txt", "r", stdin);
//freopen("output2.txt", "w", stdout);
#endif // LOCAL_DEBUG
for (int ti = ; scanf("%d", &n) == && n; ti++) {
memset(del, , sizeof(del));
memset(color, , sizeof(color));
memset(fc, , sizeof(fc));
memset(deep, , sizeof(deep));
memset(facec, , sizeof(facec));
memset(polarc, , sizeof(polarc));
char buff[];
cin.getline(buff, );
for(int i = ; i < n;i++){
cin.getline(buff, );
for (int k = ; k < ; k++) {
for (int j = ; j < n; j++) {
fc[k][i][j] = buff[(n + ) * k + j];
}
}
} int &x = facec[];
int &y = facec[];
int &z = facec[];
int &a = polarc[];
int &b = polarc[];
int &c = polarc[];
for (int fid = ; fid < ; fid++) {
for (x = ; x < n; x++) {
for (y = ; y < n; y++) {
if (fc[fid][x][y] == '.') {
deep[fid][x][y] = n;
for (z = ; z < n; z++) {
face2polar(fid, facec, polarc);
// printf("R: %d, del %d-(%d, %d, %d) : (%d, %d, %d)\n", getAns(), fid, x, y, z, a, b, c);
del[a][b][c] = true;
}
}
}
}
}
bool checkFlag = true;
while (checkFlag) {
checkFlag = false;
for (int fid = ; fid < ; fid++) {
for (x = ; x < n; x++) {
for (y = ; y < n; y++) {
for (z = deep[fid][x][y]; z < n; z++, deep[fid][x][y]++) {
face2polar(fid, facec, polarc);
if (del[a][b][c])continue;
else if (color[a][b][c] == || color[a][b][c] == fc[fid][x][y]) {
color[a][b][c] = fc[fid][x][y];
break;
}
else{
del[a][b][c] = true;
checkFlag = true;
}
}
}
}
}
}
int ans = getAns();
printf("Maximum weight: %d gram(s)\n", ans);
} return ;
}