View Compilation Error

0_0_19588959_32592.cpp: In function 'int main()':
0_0_19588959_32592.cpp:18:5: error: 'i' was not declared in this scope
 for(i=0;i<n;i++)          //双重for循环判断字符串出现次数，并用a[i]来记录
     ^
0_0_19588959_32592.cpp:27:5: error: 'i' was not declared in this scope
 for(i=0;i<n;i++)         //设最大值max=0，判断a[i]的最大值即出现最多次，把最大值的下标i赋值给k
     ^