Compilare: main.cpp: In function 'void add0(long long int)': main.cpp:14:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 14 | for(int j = 0; j < op[1][x].size(); j++) { | ~~^~~~~~~~~~~~~~~~~ main.cpp: In function 'long long int add(long long int)': main.cpp:21:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 21 | for(int j = 0; j < op[0][x].size(); j++) { | ~~^~~~~~~~~~~~~~~~~ main.cpp:28:1: warning: no return statement in function returning non-void [-Wreturn-type] 28 | } | ^ main.cpp: In function 'void upd(long long int)': main.cpp:31:9: warning: statement has no effect [-Wunused-value] 31 | for(id; id <= x.back(); id += id & (-id)) t[id]++; | ^~ main.cpp: In function 'long long int get(long long int)': main.cpp:35:9: warning: statement has no effect [-Wunused-value] 35 | for(id; id >= 1; id -= id & (-id)) c += t[id]; | ^~ main.cpp: At global scope: main.cpp:38:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type] 38 | main(){ | ^~~~ main.cpp: In function 'int main()': main.cpp:57:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 57 | for(int i = 0; i < x.size(); i++) { | ~~^~~~~~~~~~ main.cpp:80:26: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 80 | for(int j = 0; j < seg[x[i]].size(); j++) upd(seg[x[i]][j]); | ~~^~~~~~~~~~~~~~~~~~ main.cpp:82:26: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 82 | for(int j = 0; j < V[x[i]].size(); j++) ans += get(V[x[i]][j].f) * V[x[i]][j].s; | ~~^~~~~~~~~~~~~~~~