View Compilation Error

0_0_6728237_6598.cpp: In function `long long int dp(int, int)':
0_0_6728237_6598.cpp:10: error: `f' undeclared (first use this function)
0_0_6728237_6598.cpp:10: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_6728237_6598.cpp:13: error: `a' undeclared (first use this function)
0_0_6728237_6598.cpp:13: error: `gao' undeclared (first use this function)
0_0_6728237_6598.cpp:13: error: `sum' undeclared (first use this function)
0_0_6728237_6598.cpp: In function `int main()':
0_0_6728237_6598.cpp:18: error: `testdata' undeclared (first use this function)
0_0_6728237_6598.cpp:22: error: `n' undeclared (first use this function)
0_0_6728237_6598.cpp:23: error: `i' undeclared (first use this function)
0_0_6728237_6598.cpp:23: error: `rep' undeclared (first use this function)
0_0_6728237_6598.cpp:24: error: expected `;' before '{' token