Compilare: main.cpp: In function 'void solve()': main.cpp:30:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0 ; i < v1.size() ; i ++) ~~^~~~~~~~~~~ main.cpp:32:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0 ; i < v1.size() ; i ++) ~~^~~~~~~~~~~ main.cpp:39:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = i + 1 ; j < v1.size() ; j ++) ~~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:58:17: warning: unused variable 'j' [-Wunused-variable] int t , i , j , k , b , d; ^ main.cpp:56:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("strdup.in" , "r" , stdin); ^ main.cpp:57:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("strdup.out" , "w" , stdout); ^ main.cpp:59:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n" , &t); ^