Compilare: main.c: In function 'main': main.c:65:31: warning: unused variable 'source' [-Wunused-variable] int i,n,m,start,stop,pret,source; ^~~~~~ main.c:70:5: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(input,"%d%d",&n,&m); ^~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:75:9: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(input,"%d%d%d",&start,&stop,&pret); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~