prepare (1/3): 
finished

make (2/3): 
gcc -g     -c -o algorithm.o algorithm.c
gcc -g     -c -o main.o main.c
gcc -g     -c -o util.o util.c
gcc -g   -o main algorithm.o main.o util.o  
finished

clean (3/3): 
finished

all task finished, build successfully