UVA 1156 - Pixel Shuffle(模拟+置换)

UVA 1156 - Pixel Shuffle

#include <stdio.h>
#include <string.h>

const int N = 1100;
int t, n, g

, vis

, save

;
char str
, s
;

void rot(int flag) {
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
if (!flag)
save[i][j] = g[n - j - 1][i];
else
save[n - j - 1][i] = g[i][j];
}
}
for (int i = 0; i < n; i++)
for (int j = 0; j < n; j++)
g[i][j] = save[i][j];
}

void sym(int flag) {
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
save[i][j] = g[i][n - j - 1];
}
}
for (int i = 0; i < n; i++)
for (int j = 0; j < n; j++)
g[i][j] = save[i][j];
}

void bhsym(int flag) {
for (int i = 0; i < n / 2; i++) {
for (int j = 0; j < n; j++)
save[i][j] = g[i][j];
}
for (int i = n / 2; i < n; i++)
for (int j = 0; j < n; j++)
save[i][j] = g[i][n - j - 1];
for (int i = 0; i < n; i++)
for (int j = 0; j < n; j++)
g[i][j] = save[i][j];
}

void bvsym(int flag) {
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
if (i < n / 2)  save[i][j] = g[i][j];
else save[i][j] = g[3 * n / 2 - 1 - i][j];
}
}
for (int i = 0; i < n; i++)
for (int j = 0; j < n; j++)
g[i][j] = save[i][j];
}

void div(int flag) {
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
if (!flag) {
if (i % 2) save[i][j] = g[i / 2 + n / 2][j];
else save[i][j] = g[i / 2][j];
}
else {
if (i % 2) save[i / 2 + n / 2][j] = g[i][j];
else save[i / 2][j] = g[i][j];
}
}
}
for (int i = 0; i < n; i++)
for (int j = 0; j < n; j++)
g[i][j] = save[i][j];
}

void mix(int flag) {
for (int i = 0; i < n; i++){
for (int j = 0; j < n; j++){
if (i % 2 == 0){
if (flag) {
if (j % 2 == 0) save[i][j] = g[i][j / 2];
else save[i][j] = g[i + 1][j / 2];
}
else {
if (j % 2 == 0) save[i][j / 2] = g[i][j];
else save[i + 1][j / 2] = g[i][j];
}
}else{
if (flag) {
if(j % 2 == 0) save[i][j] = g[i - 1][n / 2 + j / 2];
else save[i][j] = g[i][n / 2 + j / 2];
}
else {
if(j % 2 == 0) save[i - 1][n / 2 + j / 2] = g[i][j];
else save[i][n / 2 + j / 2] = g[i][j];
}
}
}
}
for (int i = 0; i < n; i++)
for (int j = 0; j < n; j++)
g[i][j] = save[i][j];
}

void change(char *str) {
int len = strlen(str);
int flag = 1;
if (str[0] == '-') {
flag = 0;
str++;
}
if (strcmp(str, "tor") == 0) rot(flag);
else if (strcmp(str, "mys") == 0) sym(flag);
else if (strcmp(str, "myshb") == 0) bhsym(flag);
else if (strcmp(str, "mysvb") == 0) bvsym(flag);
else if (strcmp(str, "vid") == 0) div(flag);
else if (strcmp(str, "xim") == 0) mix(flag);
}

void tra() {
int len = strlen(str);
int sn = 0;
for (int i = len - 1; i >= 0; i--) {
if (str[i] == ' ') {
s[sn] = '\0';
change(s);
sn = 0;
}
else {
s[sn++] = str[i];
}
}
s[sn] = '\0';
change(s);
}

int gcd(int a, int b) {
if (!b) return a;
return gcd(b, a % b);
}

int lcm(int a, int b) {
return a / gcd(a, b) * b;
}

int solve() {
int ans = 1;
memset(vis, 0, sizeof(vis));
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
if (!vis[i][j]) {
vis[i][j] = 1;
int cnt = 1;
int x = g[i][j] / n;
int y = g[i][j] % n;
while (!vis[x][y]) {
cnt++;
vis[x][y] = 1;
int t = g[x][y] / n;
y = g[x][y] % n;
x = t;
}
ans = lcm(ans, cnt);
}
}
}
return ans;
}

void init() {
scanf("%d", &n);
getchar();
gets(str);
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
g[i][j] = i * n + j;
}
}
}

int main() {
scanf("%d", &t);
while (t--) {
init();
tra();
printf("%d\n", solve());
if (t) printf("\n");
}
return 0;
}