Compilare: main.cpp: In function 'int main()': main.cpp:37:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < b[i].size(); ++j) { ~~^~~~~~~~~~~~~ main.cpp:23:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("scara3.in", "r", stdin); ^ main.cpp:24:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("scara3.out", "w", stdout); ^ main.cpp:25:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &k); ^ main.cpp:30:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] b[x].push_back({0, y}); ^ main.cpp:31:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &l); ^ main.cpp:34:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] b[x].push_back({1, y}); ^