Jump Game II

Given an array of non-negative integers, you are initially positioned at the first index of the array.

Each element in the array represents your maximum jump length at that position.

Your goal is to reach the last index in the minimum number of jumps.

For example:
Given array A = [2,3,1,1,4]

The minimum number of jumps to reach the last index is 2. (Jump 1 step from index 0 to 1, then 3 steps to the last index.)

此次犯了一個大錯誤，導致結果一直出不來很鬱悶。後來斷點下，再度娘下，終於發現了，memset的用法錯誤。以前只是初始化0，不會有問題，現在用來初始化大int的值出錯，原因是按字節初始化！以後記住！

 //dp 問題 ，dp[i] = min(dp[j])+1;(0<=j<i , 滿足條件a[j]+j > i的情況（即能覆蓋i） ) //dp[i] 爲0-i的的最少步數
    int jump_game(int *a,int n)
    {
    	if (a == NULL || n <= 0)
    	{
    		return 0;
    	}
    
    	int *count = new int [n]; 
    
    	//memset(count,0,sizeof(int)*n);//初始化0可以。其他值不行，因是按字節賦值
    	
    	count[0] = 0;
    	for (int i = 1 ;i < n ;i++)
    	{
    		count[i]= INT_MAX;
    	}
    
    	for (int i = 1; i < n;i++)
    	{
    		 for (int j = 0;j < i ;j++)
    		 {
    			 if (a[j] + j >= i)//覆蓋範圍！！
    			 {
    				 if (count[i] > count[j]+1)
    				 {
    					 count[i] = count[j]+1; 
    					 //可優化！否則超時！！
    					break;
    				 }
    			 }
    		 }
    	}
    
    	 
    	int res = count[n-1];
    	delete []count;
    	return  res;
    }