第二题:
int[][] test = new int[12][31];
int max = 0;
int currentM =0,currentD=0;
String line ;
while((line = in.readLine())!=null){
int m = Integer.parser(line.substring(4,6));
int d = Integer.parser(line.substring(6,8));
test[m][d]++;
if(test[m][d]>max){
   max = test[m][d];
   currentM = m;
   currentD = d;
}
}

int[][] test = new int[12][31];
int max = 0;
int currentM =0,currentD=0;
String line ;
while((line = in.readLine())!=null){
int m = Integer.parser(line.substring(4,6));
int d = Integer.parser(line.substring(6,8));
test[m][d]++;
if(test[m][d]>max){
   max = test[m][d];
   currentM = m;
   currentD = d;
}
}