Compilare: user.cpp: In function ‘int dijkstra_small(int, int)’: user.cpp:37:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0; j < nod_dist[i].size(); j++) { ^ user.cpp:39:53: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k = 0; k < adj[nod_dist[i][j]].size(); k++) { ^ user.cpp: In function ‘int main()’: user.cpp:55:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pscnv.in", "r", stdin); ^ user.cpp:56:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pscnv.out", "w", stdout); ^ user.cpp:60:43: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d\n", &n, &m, &x, &y); ^ user.cpp:62:19: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(buff); ^ /tmp/ccBN6hD3.o: In function `main': user.cpp:(.text.startup+0x9d): warning: the `gets' function is dangerous and should not be used.