Compilare: main.cpp: In function 'int main()': main.cpp:10:15: warning: unused variable 'k' [-Wunused-variable] int n,i,j,k,pas; ^ main.cpp:10:17: warning: unused variable 'pas' [-Wunused-variable] int n,i,j,k,pas; ^~~ main.cpp:8:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("redu.in","r",stdin); ^ main.cpp:9:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("redu.out","w",stdout); ^ main.cpp:11:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&n); ^ main.cpp:12:27: warning: ignoring return value of 'char* fgets(char*, int, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fgets(str+1,501,stdin); ^ main.cpp:17:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&cost[i][j]); ^