update shuffle_vector() (#437)

field.cpp

@@ -957,14 +957,14 @@ void field::shuffle(uint8 playerid, uint8 location) {
 		}
 	}
 	if(location == LOCATION_HAND || !(core.duel_options & DUEL_PSEUDO_SHUFFLE)) {
-		uint32 s = (uint32)svector.size();
+		int32 s = (int32)svector.size();
 		if(location == LOCATION_EXTRA)
-			s = s - player[playerid].extra_p_count;
+			s = s - (int32)player[playerid].extra_p_count;
 		if(s > 1) {
 			if (core.duel_options & DUEL_OLD_REPLAY)
-				pduel->random.shuffle_vector_old(svector);
+				pduel->random.shuffle_vector_old(svector, 0, s - 1);
 			else
-				pduel->random.shuffle_vector(svector);
+				pduel->random.shuffle_vector(svector, 0, s - 1);
 			reset_sequence(playerid, location);
 		}
 	}

mtrandom.h

@@ -44,20 +44,26 @@ public:
 		return result;
 	}
 	
-	// Fisher-Yates shuffle
+	// Fisher-Yates shuffle v[a]~v[b]
 	template<typename T>
-	void shuffle_vector(std::vector<T>& v) {
-		int n = (int)v.size();
-		for (int i = 0; i < n - 1; ++i) {
-			int r = get_random_integer(i, n - 1);
+	void shuffle_vector(std::vector<T>& v, int a = -1, int b = -1) {
+		if (a < 0)
+			a = 0;
+		if (b < 0)
+			b = (int)v.size() - 1;
+		for (int i = a; i < b; ++i) {
+			int r = get_random_integer(i, b);
 			std::swap(v[i], v[r]);
 		}
 	}
 	template<typename T>
-	void shuffle_vector_old(std::vector<T>& v) {
-		int n = (int)v.size();
-		for (int i = 0; i < n - 1; ++i) {
-			int r = get_random_integer_old(i, n - 1);
+	void shuffle_vector_old(std::vector<T>& v, int a = -1, int b = -1) {
+		if (a < 0)
+			a = 0;
+		if (b < 0)
+			b = (int)v.size() - 1;
+		for (int i = a; i < b; ++i) {
+			int r = get_random_integer_old(i, b);
 			std::swap(v[i], v[r]);
 		}
 	}