Code:
$ gcc -Wall -Wextra foo.c
foo.c: In function ‘main’:
foo.c:51:14: warning: assignment from incompatible pointer type [-Wincompatible-pointer-types]
board=(char*)malloc(M*sizeof(char));
^
foo.c:106:11: warning: format ‘%c’ expects argument of type ‘char *’, but argument 2 has type ‘int’ [-Wformat=]
scanf("%c",board_interaction);
^
foo.c:4:115: warning: unused variable ‘position_j’ [-Wunused-variable]
int N,M,i,j,diff,number_of_enemies=0,number_of_obstacles=0,money=0,total_money=0,enemies_to_kill,a,b,position_i=0,position_j=0;
^
foo.c:4:102: warning: unused variable ‘position_i’ [-Wunused-variable]
int N,M,i,j,diff,number_of_enemies=0,number_of_obstacles=0,money=0,total_money=0,enemies_to_kill,a,b,position_i=0,position_j=0;
^
foo.c:4:82: warning: variable ‘enemies_to_kill’ set but not used [-Wunused-but-set-variable]
int N,M,i,j,diff,number_of_enemies=0,number_of_obstacles=0,money=0,total_money=0,enemies_to_kill,a,b,position_i=0,position_j=0;
^
foo.c:106:5: warning: ‘board_interaction’ is used uninitialized in this function [-Wuninitialized]
scanf("%c",board_interaction);
^