Compilare: main.cpp: In function 'int main()': main.cpp:76:10: warning: statement has no effect [-Wunused-value] for(a;a<=b;a++){ ^ main.cpp:47:36: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d%d%d%d",&t,&n,&a,&b); ^ main.cpp:50:25: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d",&x); ^