Compilare: user.cpp: In function ‘void backtrack(int)’: user.cpp:8:66: warning: statement has no effect [-Wunused-value] if (nr!=k+1) {for (i=sol[nr-1]+1;i<=n;i++) if (uze[i]==0) {uze[i]==1; ^ user.cpp: In function ‘int main()’: user.cpp:25:32: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d %d\n",&n,&k,&d); ^ user.cpp:26:44: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (i=1;i<=n;i++){fscanf(f,"%d ",&v[i][0]); ^ user.cpp:27:68: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (j=1;j<=v[i][0];j++) fscanf(f,"%d",&v[i][j]); ^