Compilare: user.cpp: In function ‘int main()’: user.cpp:171:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0; j < mp.size(); ++j) { ^ user.cpp:183:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0; j < mp.size(); ++j) ^ user.cpp:131:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rutier.in", "r", stdin); ^ user.cpp:132:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rutier.out", "w", stdout); ^ user.cpp:137:44: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] int a1, a2; scanf("%d%d", &a1, &a2); ^ user.cpp:148:45: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &a[i], &b[i], &c[i]); ^