cgram(6): use standard cursor keys, use standard shuffle algorithm

The previous shuffle algorithm asked for 100 random numbers, on average.
The new algorithm asks exactly for 26 random numbers.

Curses predefines numeric constants for keys, and there is no apparent
reason not to use these standard keys for cursor movement.

1 files changed, 13 insertions, 9 deletions

diff --git a/cgram/cgram.c b/cgram/cgram.c
index 76ea55fb..5e5dd556 100644
--- a/cgram/cgram.c
+++ b/cgram/cgram.c
@@ -120,16 +120,13 @@ static void readquote(void) {
 }
 
 static void encode(void) {
-   int used[26];
-   for (int i=0; i<26; i++) used[i] = 0;
-
    int key[26];
-   int keypos=0;
-   while (keypos < 26) {
-      int c = random()%26;
-      if (used[c]) continue;
-      key[keypos++] = c;
-      used[c] = 1;
+   for (int i=0; i<26; i++) key[i] = i;
+   for (int i=26; i>1; i--) {
+      int c = random() % i;
+      int t = key[i-1];
+      key[i-1] = key[c];
+      key[c] = t;
    }
 
    for (int y=0; y<lines.num; y++) {
@@ -244,9 +241,11 @@ static void loop(void) {
       int ch = getch();
       switch (ch) {
        case 1: /* ^A */
+       case KEY_BEG:
 	curx=0;
 	break;
        case 2: /* ^B */
+       case KEY_LEFT:
 	if (curx > 0) {
 	   curx--;
 	}
@@ -256,9 +255,11 @@ static void loop(void) {
 	}
 	break;
        case 5: /* ^E */
+       case KEY_END:
 	curx = strlen(lines.v[cury]);
 	break;
        case 6: /* ^F */
+       case KEY_RIGHT:
 	if (curx < strlen(lines.v[cury])) {
 	   curx++;
 	}
@@ -271,6 +272,7 @@ static void loop(void) {
 	clear();
 	break;
        case 14: /* ^N */
+       case KEY_DOWN:
 	if (cury < lines.num-1) {
 	   cury++;
 	}
@@ -282,6 +284,7 @@ static void loop(void) {
 	}
 	break;
        case 16: /* ^P */
+       case KEY_UP:
 	if (cury > 0) {
 	   cury--;
 	}
@@ -335,6 +338,7 @@ int main(void) {
    encode();
    opencurses();
 
+   keypad(stdscr, TRUE);
    loop();
 
    closecurses();