tickets.cpp: In function 'long long int find_maximum(int, std::vector<std::vector<int> >)':
tickets.cpp:23:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
23 | for(int q = 0;q < x.size();q++) {
| ~~^~~~~~~~~~
tickets.cpp:24:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
24 | for(int w = 0;w < x[0].size();w++) {
| ~~^~~~~~~~~~~~~
tickets.cpp:61:9: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<name> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
61 | if(j == upper.size()) break;
| ~~^~~~~~~~~~~~~~~
tickets.cpp:72:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<name> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
72 | while(j < lower.size()) {
| ~~^~~~~~~~~~~~~~
tickets.cpp:74:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<name>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
74 | for(int q = 0;q < lower[j].size();q++) {
| ~~^~~~~~~~~~~~~~~~~
tickets.cpp:79:5: warning: statement has no effect [-Wunused-value]
79 | r%+k;
| ~^~~
tickets.cpp:18:6: warning: unused variable 'M' [-Wunused-variable]
18 | int M = x[0].size();
| ^