View Compilation Error

0_0_38661232_6202.cpp: In function 'int main()':
0_0_38661232_6202.cpp:30:3: error: 'memset' was not declared in this scope
   memset(tree,0,sizeof(tree));
   ^~~~~~
0_0_38661232_6202.cpp:30:3: note: 'memset' is defined in header '<cstring>'; did you forget to '#include <cstring>'?
0_0_38661232_6202.cpp:5:1:
+#include <cstring>
 #define lson k<<1
0_0_38661232_6202.cpp:30:3:
   memset(tree,0,sizeof(tree));
   ^~~~~~
0_0_38661232_6202.cpp:32:10: error: 'b' was not declared in this scope
   memset(b,0,sizeof(b));
          ^
0_0_38661232_6202.cpp:33:10: error: 'c' was not declared in this scope
   memset(c,0,sizeof(c));
          ^
0_0_38661232_6202.cpp:34:3: error: 'm' was not declared in this scope
   m=0x3f3f3f3f,tot=0;
   ^
0_0_38661232_6202.cpp:34:16: error: 'tot' was not declared in this scope
   m=0x3f3f3f3f,tot=0;
                ^~~
0_0_38661232_6202.cpp:34:16: note: suggested alternative: 'ltoa'
   m=0x3f3f3f3f,tot=0;
                ^~~
                ltoa