View Compilation Error

0_0_23480759_20505.cpp: In function 'int main()':
0_0_23480759_20505.cpp:13:13: error: 'i' was not declared in this scope
         for(i=3;i<=50;i++)
             ^
0_0_23480759_20505.cpp:19:16: error: 'i' was not declared in this scope
         c[0]=c[i-2];//*c【n%（i-2）】对应的数即为所求第n个数对7mod结果 ,因为对7求余等0即为循环数列的最后一个，所以把最后一个循环数存c0*/
                ^