Compilare: main.cpp: In function 'void solve(int, int)': main.cpp:164:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 1; j < ids[i].size(); j++) { ~~^~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:205:12: warning: unused variable 'j' [-Wunused-variable] int i, j, n, k; ^ main.cpp: In function 'char nextch()': main.cpp:12:34: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buf, 1, MAXBUF, fi); ^ main.cpp: In function 'void solve(int, int)': main.cpp:173:31: warning: 'new_val' may be used uninitialized in this function [-Wmaybe-uninitialized] while(last < n && tot != val) { ~~~~^~~~~~