View Compilation Error

0_0_16592266_18816.cpp: In function 'int main()':
0_0_16592266_18816.cpp:51:5: error: redefinition of 'int main()'
 int main()
     ^
0_0_16592266_18816.cpp:3:5: note: 'int main()' previously defined here
 int main()
     ^
0_0_16592266_18816.cpp:68:8: error: 'a' was not declared in this scope
    if (a[i]>1 && str[i] != str[i - 1])
        ^
0_0_16592266_18816.cpp:70:8: error: 'a' was not declared in this scope
    if (a[i] == 1 && str[i] != str[i - 1])
        ^