Step

AtCoder

IDabc176_c

Time2000ms

Memory256MB

Difficulty—

$N$ persons are standing in a row. The height of the $i$\-th person from the front is $A_i$. We want to have each person stand on a stool of some heights - at least zero - so that the following condition is satisfied for every person: Condition: Nobody in front of the person is taller than the person. Here, the height of a person includes the stool. Find the minimum total height of the stools needed to meet this goal. ## Constraints * $1 \leq N \leq 2\times 10^5$ * $1 \leq A_i \leq 10^9$ * All values in input are integers. ## Input Input is given from Standard Input in the following format: $N$ $A_1$ $\ldots$ $A_N$ [samples]

Samples

Input #1

5
2 1 5 4 3

Output #1

4

If the persons stand on stools of heights $0$, $1$, $0$, $1$, and $2$, respectively, their heights will be $2$, $2$, $5$, $5$, and $5$, satisfying the condition.
We cannot meet the goal with a smaller total height of the stools.

Input #2

5
3 3 3 3 3

Output #2

0

Giving a stool of height $0$ to everyone will work.

API Response (JSON)

{
  "problem": {
    "name": "Step",
    "description": {
      "content": "$N$ persons are standing in a row. The height of the $i$\\-th person from the front is $A_i$. We want to have each person stand on a stool of some heights - at least zero - so that the following condit",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "abc176_c"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "$N$ persons are standing in a row. The height of the $i$\\-th person from the front is $A_i$.\nWe want to have each person stand on a stool of some heights - at least zero - so that the following condit...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

Full JSON Raw Segments