Compilare: main.cpp: In function 'int main()': main.cpp:55:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pst < scos_st[i].size() && pdr < scos_dr[i].size()) { ~~~~^~~~~~~~~~~~~~~~~~~ main.cpp:55:47: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pst < scos_st[i].size() && pdr < scos_dr[i].size()) { ~~~~^~~~~~~~~~~~~~~~~~~ main.cpp:65:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pst < scos_st[i].size()) { ~~~~^~~~~~~~~~~~~~~~~~~ main.cpp:69:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pdr < scos_dr[i].size()) { ~~~~^~~~~~~~~~~~~~~~~~~