prepare (1/3): 
finished

make (2/3): 
g++ -g -Wall -O2 -o main.o -c main.cpp
In file included from main.cpp:8:0:
fib_heap.h: In instantiation of 'fib_heap<TYPE, COMP>::~fib_heap() [with TYPE = point*; COMP = compare]':
main.cpp:312:1:   required from here
fib_heap.h:89:8: warning: variable 'temp' set but not used [-Wunused-but-set-variable]
   TYPE temp;
        ^~~~
In file included from main.cpp:7:0:
binary_heap.h: In member function 'const TYPE& binary_heap<TYPE, COMP>::get_min() const [with TYPE = point*; COMP = compare]':
binary_heap.h:88:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
binary_heap.h: In member function 'TYPE binary_heap<TYPE, COMP>::dequeue_min() [with TYPE = point*; COMP = compare]':
binary_heap.h:82:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
In file included from main.cpp:9:0:
unsorted_heap.h: In member function 'const TYPE& unsorted_heap<TYPE, COMP>::get_min() const [with TYPE = point*; COMP = compare]':
unsorted_heap.h:100:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
unsorted_heap.h: In member function 'TYPE unsorted_heap<TYPE, COMP>::dequeue_min() [with TYPE = point*; COMP = compare]':
unsorted_heap.h:86:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
In file included from main.cpp:8:0:
fib_heap.h: In member function 'const TYPE& fib_heap<TYPE, COMP>::get_min() const [with TYPE = point*; COMP = compare]':
fib_heap.h:222:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
fib_heap.h: In member function 'TYPE fib_heap<TYPE, COMP>::dequeue_min() [with TYPE = point*; COMP = compare]':
fib_heap.h:217:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
main.cpp: In function 'int main(int, char**)':
main.cpp:122:9: warning: 'PQ' may be used uninitialized in this function [-Wmaybe-uninitialized]
    brief(width, height, start_x, start_y, end_x, end_y, grid, PQ);
    ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
g++ -g -Wall -O2 -o main main.o 
finished

clean (3/3): 
finished

all task finished, build successfully