HDU 1029 Ignatius and the Princess IV

Water problem Ah, well the DP it

The first idea is hash, but the range of the problem data is not given. I've been trying to figure out how to use DP

Then looked at the problem-solving report, the solution is too simple, because there must be a number of occurrences than all the other number of times added up, so use a counter to cancel each other on it.

#include <stdio.h>int main () {#ifndef online_judgefreopen ("In.txt", "R", stdin), #endifint n;while (scanf ("%d", &n)!=eof) {int Num,cnt=0,ans;while (n--) {scanf ("%d", &num), if (cnt==0) {ans=num;cnt++;} Else{if (ans==num) Cnt++;else cnt--;}} printf ("%d\n", ans);}}

HDU 1029 Ignatius and the Princess IV