View Compilation Error

0_0_21560939_30916.cpp: In function 'int main()':
0_0_21560939_30916.cpp:17:21: error: invalid conversion from 'int' to 'const char*' [-fpermissive]
    int len2=strlen(t);
                     ^
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/cstring:42:0,
                 from 0_0_21560939_30916.cpp:3:
GCC4.9.2/x86_64-w64-mingw32/include/string.h:54:18: note: initializing argument 1 of 'size_t strlen(const char*)'
   size_t __cdecl strlen(const char *_Str);
                  ^
0_0_21560939_30916.cpp:20:17: error: invalid types 'int[int]' for array subscript
     if(s[i]==t[j]){
                 ^