Optimize maplist shuffle algorithm by reducing the number of strcats

diff --git a/qcsrc/server/intermission.qc b/qcsrc/server/intermission.qc
index b2652f7d8d9b27cc0da41d128d31bccf88383603..9392c2399f3942aac3a2598568b4e7111be6971e 100644 (file)
--- a/qcsrc/server/intermission.qc
+++ b/qcsrc/server/intermission.qc
@@ -210,9 +210,9 @@ float MaplistMethod_Random() // random map selection
        return -1;
 }
 
-float MaplistMethod_Shuffle(float exponent) // more clever shuffling
 // the exponent sets a bias on the map selection:
 // the higher the exponent, the less likely "shortly repeated" same maps are
+float MaplistMethod_Shuffle(float exponent) // more clever shuffling
 {
        float i, j, imax, insertpos;
 
@@ -232,11 +232,21 @@ float MaplistMethod_Shuffle(float exponent) // more clever shuffling
 
                // insert the current map there
                newlist = "";
-               for(j = 1; j < insertpos; ++j)                 // i == 1: no loop, will be inserted as first; however, i == 1 has been excluded above
-                       newlist = strcat(newlist, " ", argv(j));
+               for(j = 1; j < insertpos; ) // i == 1: no loop, will be inserted as first; however, i == 1 has been excluded above
+               {
+                       if (j + 2 < insertpos)
+                               newlist = strcat(newlist, " ", argv(j++), " ", argv(j++), " ", argv(j++));
+                       else
+                               newlist = strcat(newlist, " ", argv(j++));
+               }
                newlist = strcat(newlist, " ", argv(0));       // now insert the just selected map
-               for(j = insertpos; j < Map_Count; ++j)         // i == Map_Count: no loop, has just been inserted as last
-                       newlist = strcat(newlist, " ", argv(j));
+               for(j = insertpos; j < Map_Count; ) // i == Map_Count: no loop, has just been inserted as last
+               {
+                       if (j + 2 < Map_Count)
+                               newlist = strcat(newlist, " ", argv(j++), " ", argv(j++), " ", argv(j++));
+                       else
+                               newlist = strcat(newlist, " ", argv(j++));
+               }
                newlist = substring(newlist, 1, strlen(newlist) - 1);
                cvar_set("g_maplist", newlist);
                Map_Count = tokenizebyseparator(autocvar_g_maplist, " ");