#include <stdio.h> void runyear(int* year,int *month) { int arr[13] = {0}; if(((*year % 4 == 0) &&(*year % 100 !=0)) || (*year % 400 == 0)) { int arr[13] = {0,31,29,31,30,31,30,31,31,30,31,30,31}; printf("%d\n",arr[*month]); } else { int arr[13] = {0,31,28,31,30,31,30,31,31,3...