View Compilation Error

0_0_39666421_14957.cpp: In function 'int main(int, char**)':
0_0_39666421_14957.cpp:4:9: error: 'printf' was not declared in this scope
    4 |         printf("请输入行数：\n");
      |         ^~~~~~
0_0_39666421_14957.cpp:1:1: note: 'printf' is defined in header '<cstdio>'; did you forget to '#include <cstdio>'?
  +++ |+#include <cstdio>
    1 | int main(int argc, char *argv[]) {
0_0_39666421_14957.cpp:5:9: error: 'scanf' was not declared in this scope
    5 |         scanf("%d",&len);
      |         ^~~~~