savrsen.cpp:21:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
main()
^
savrsen.cpp: In function 'int main()':
savrsen.cpp:42:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i = 0; i < v.size(); i++)
~~^~~~~~~~~~
savrsen.cpp: In function 'void free()':
savrsen.cpp:17:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
freopen("A.in", "r", stdin);
~~~~~~~^~~~~~~~~~~~~~~~~~~~
savrsen.cpp:18:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
freopen("A.out", "w", stdout);
~~~~~~~^~~~~~~~~~~~~~~~~~~~~~