Compilare: main.cpp: In function 'int main()': main.cpp:26:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(x-1 > m[y].size()-1 || !m[y].size()) ~~~~^~~~~~~~~~~~~~~ main.cpp:7:16: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ main.cpp:11:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^ main.cpp:21:16: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&q); ^ main.cpp:25:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&x,&y); ^