Compilare: main.cpp:9:30: warning: suggest parentheses around '+' inside '<<' [-Wparentheses] unsigned int n, l, u, x[1<<20+1]; ~~^~ main.cpp: In function 'long long int solve(int)': main.cpp:15:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1; i<=n; ++i) ~^~~ main.cpp:18:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(ap.size()>l) ~~~~~~~~~^~ main.cpp: In function 'int main()': main.cpp:32:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1; i<=n; ++i) fin>>x[i]; ~^~~