View Compilation Error

0_0_27126540_30330.cpp: In function 'void getnext(char*)':
0_0_27126540_30330.cpp:10:20: error: 'strlen' was not declared in this scope
  int len = strlen(s);
                    ^
0_0_27126540_30330.cpp: In function 'int getindex(int, char*)':
0_0_27126540_30330.cpp:23:22: error: 'strlen' was not declared in this scope
  int len = strlen(tmp);
                      ^
0_0_27126540_30330.cpp: In function 'int main()':
0_0_27126540_30330.cpp:45:16: error: 'strlen' was not declared in this scope
   tn = strlen(t);
                ^