View Compilation Error

0_0_21000098_15622.cpp: In function 'bool init()':
0_0_21000098_15622.cpp:60:17: error: 'strlen' was not declared in this scope
   L = strlen(ord);
                 ^
0_0_21000098_15622.cpp: In function 'void bfs(int, int)':
0_0_21000098_15622.cpp:84:35: error: 'memset' was not declared in this scope
   memset(visit , 0 , sizeof(visit));
                                   ^
0_0_21000098_15622.cpp: In function 'void dfs(int, int, int)':
0_0_21000098_15622.cpp:105:12: error: expected primary-expression before '?' token
       ans <?= now;
            ^
0_0_21000098_15622.cpp:105:13: error: expected primary-expression before '=' token
       ans <?= now;
             ^
0_0_21000098_15622.cpp:105:18: error: expected ':' before ';' token
       ans <?= now;
                  ^
0_0_21000098_15622.cpp:105:18: error: expected primary-expression before ';' token
0_0_21000098_15622.cpp: In function 'void work()':
0_0_21000098_15622.cpp:116:32: error: 'memset' was not declared in this scope
   memset(dis , -1 , sizeof(dis));
                                ^