View Compilation Error

0_0_35833793_16619.cpp: In function 'int main()':
0_0_35833793_16619.cpp:15:16: error: 'flag1' was not declared in this scope
    if(s[a[i]]!=flag1)
                ^
0_0_35833793_16619.cpp:20:16: error: 'flag1' was not declared in this scope
    if(d[a[i]]!=flag1)
                ^