Compilare: main.c: In function 'front': main.c:167:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ main.c: In function 'main': main.c:234:2: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d %d %d", &n, &m, &src); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:238:9: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d %d", &x, &y); ^~~~~~~~~~~~~~~~~~~~~~~~~~~