Compilare: main.c: In function 'main': main.c:15:2: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d %d", &N, &M); ^~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:20:6: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d %d %d", &B[i].left, &B[i].right, &B[i].jump, &B[i].weight); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~