Index: aoc2015.c
==================================================================
--- aoc2015.c
+++ aoc2015.c
@@ -5,54 +5,41 @@
 #include "aocdailies.h"
 #include "aocutils.h"
 
 void aoc201505(char *data, size_t len) {
     (void)len; // unused argument
-    unsigned lines = 0, nice = 0, nice2 = 0;
+    unsigned nice = 0, nice2 = 0;
     char *line = strtok(data, "\n"), *curr;
     while (line) {
-        lines++; // used in Part Two
-        if (!strstr(line, "ab")) {
-            if (!strstr(line, "cd")) {
-                if (!strstr(line, "pq")) {
-                    if (!strstr(line, "xy")) {
-                        for (curr = line; curr[1]; curr++) {
-                            if (curr[0] == curr[1]) break;
-                        }
-                        if (curr[0] == curr[1]) {
-                            unsigned vowels = 0;
-                            for (curr = line; *curr; curr++) {
-                                if (strchr("aeiou", *curr)) vowels++;
-                                if (vowels == 3) break;
-                            }
-                            nice += (vowels == 3);
-                        }
-                    }
-                }
-            }
-        }
+        unsigned vowels = 0;
+        bool twice = false;
+        bool hasab, hascd, haspq, hasxy;
+        bool pair = false, hugged = false; // Part Two
+
+        curr = line;
+        if (strchr("aeiou", *curr)) vowels++;
+        if (curr[0] == curr[1]) twice = true;
+        for (curr = line + 1; *curr; curr++) {
+            if (strchr("aeiou", *curr)) vowels++;
+            if (curr[0] == curr[1]) twice = true;
+            if (curr[-1] == curr[1]) hugged = true;
+            char pp[3] = {curr[-1], curr[0], 0};
+            if (strstr(curr + 1, pp)) pair = true;
+        }
+        hasab = (strstr(line, "ab") != NULL);
+        hascd = (strstr(line, "cd") != NULL);
+        haspq = (strstr(line, "pq") != NULL);
+        hasxy = (strstr(line, "xy") != NULL);
+
+        if ((vowels >= 3) && twice && !hasab && !hascd && !haspq && !hasxy) {
+            nice++;
+        }
+        if (pair && hugged) nice2++;
+
         line = strtok(NULL, "\n");
     }
     printf("There are %u nice strings.\n", nice);
-
-    line = data;
-    bool pair, hugged;
-    while (lines--) {
-        pair = hugged = false;
-        for (curr = line; curr[3]; curr++) {
-            char twostr[3] = {curr[0], curr[1], 0};
-            if (strstr(curr+2, twostr)) pair = true;
-            if (curr[0] == curr[2]) hugged = true;
-            if (pair && hugged) break;
-        }
-        if (pair) {
-            if (hugged) nice2++;
-            else if (curr[0] == curr[2]) nice2++;
-            else if (curr[1] == curr[3]) nice2++;
-        }
-        line += 1 + strlen(line); // go to next line, skip '\0' left from strtok
-    }
     printf("There are %u nice strings under the new rules.\n", nice2);
 }
 
 void aoc201504(char *data, size_t len) {
     data[--len] = 0; // remove newline, adjust `len`