View Compilation Error

0_0_20201101_16442.cpp: In function 'void DIJ(int)':
0_0_20201101_16442.cpp:20:13: error: unable to find numeric literal operator 'operator""f'
 #define INF 3f
             ^
0_0_20201101_16442.cpp:41:11: note: in expansion of macro 'INF'
   int min=INF;
           ^
0_0_20201101_16442.cpp:20:13: note: use -std=gnu++11 or -fext-numeric-literals to enable more built-in suffixes
 #define INF 3f
             ^
0_0_20201101_16442.cpp:41:11: note: in expansion of macro 'INF'
   int min=INF;
           ^
0_0_20201101_16442.cpp: In function 'int main()':
0_0_20201101_16442.cpp:20:13: error: unable to find numeric literal operator 'operator""f'
 #define INF 3f
             ^
0_0_20201101_16442.cpp:67:12: note: in expansion of macro 'INF'
   memset(a,INF,sizeof(a));
            ^
0_0_20201101_16442.cpp:20:13: note: use -std=gnu++11 or -fext-numeric-literals to enable more built-in suffixes
 #define INF 3f
             ^
0_0_20201101_16442.cpp:67:12: note: in expansion of macro 'INF'
   memset(a,INF,sizeof(a));
            ^