Compilare: user.c: In function ‘suma’: user.c:25:3: warning: implicit declaration of function ‘abs’ [-Wimplicit-function-declaration] if ( abs(lim1 - X ) % 2 == 0 && abs(lim2 - Y ) % 2 == 0 ) { ^ user.c: In function ‘main’: user.c:58:10: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin, "%d%d%d%d", &n, &m, &X, &Y ) ; ^ user.c:62:14: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin, "%d", &mat[i][j] ) ; ^