View Compilation Error

0_0_30425434_25205.cpp: In function 'int main()':
0_0_30425434_25205.cpp:20:18: error: 'p' was not declared in this scope
    scanf("%lf", &p[i]);
                  ^
0_0_30425434_25205.cpp:22:8: error: 'p' was not declared in this scope
   sort(p + 1, p + 1 + n, cmp);
        ^