Compilare: user.cpp:19:73: warning: multi-character character constant [-Wmultichar] if(x==0) {int z=upper_bound(v+1,v+n+1,y)-v-1; if(v[z]==y) g<<z<<'/n'; else g<<-1<<endl;} ^ user.cpp:21:72: warning: multi-character character constant [-Wmultichar] if(x==1) {int z=upper_bound(v+1,v+n+1,y)-v-1;if(v[z]==y) g<<z<<'/n'; else g<<lower_bound(v+1,v+n+1,y)-v-1<<'/n';} ^ user.cpp:21:116: warning: multi-character character constant [-Wmultichar] if(x==1) {int z=upper_bound(v+1,v+n+1,y)-v-1;if(v[z]==y) g<<z<<'/n'; else g<<lower_bound(v+1,v+n+1,y)-v-1<<'/n';} ^ user.cpp:23:71: warning: multi-character character constant [-Wmultichar] if(x==2) {int z=lower_bound(v+1,v+n+1,y)-v; if(v[z]==y) g<<z<<'/n'; else g<<upper_bound(v+1,v+n+1,y)-v<<'/n';} ^ user.cpp:23:113: warning: multi-character character constant [-Wmultichar] if(x==2) {int z=lower_bound(v+1,v+n+1,y)-v; if(v[z]==y) g<<z<<'/n'; else g<<upper_bound(v+1,v+n+1,y)-v<<'/n';} ^ user.cpp: In function ‘int main()’: user.cpp:9:9: warning: unused variable ‘x’ [-Wunused-variable] int x; ^