fix

lab1/Makefile

@@ -2,15 +2,18 @@
 MPICC ?= mpicc
 MPIRUN ?= mpirun
 CFLAGS ?= -O2 -Wall
-TARGET := $(basename $(SRC))
 SRC := mpi_hello_world.c serial_pi.c mpi_pi.c
+TARGET := $(basename $(SRC))
 
 .PHONY: all clean run
 
 all: $(TARGET)
 
-$(TARGET): $(SRC)
-	$(MPICC) $(CFLAGS) -o $@ $<
+mpi_%: mpi_%.c
+    $(MPICC) $(CFLAGS) -o $@ $<
+
+serial_%: serial_%.c
+    $(CC) $(CFLAGS) -o $@ $<
 
 run: $(TARGET)
 	$(MPIRUN) -np 4 ./$@