UVA 1156 - Pixel Shuffle

题目链接

题意：依据题目中的变换方式，给定一串变换方式，问须要运行几次才干回复原图像

思路：这题恶心的一比，先模拟求出一次变换后的相应的矩阵，然后对该矩阵求出全部循环长度，全部循环长度的公倍数就是答案

代码：

#include <stdio.h>
#include <string.h>const int N = 1100;
int t, n, g[N][N], vis[N][N], save[N][N];
char str[N], s[N];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];elsesave[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;
}