Problem:
Score : 300 points

Problem Statement

In a flower bed, there are N flowers, numbered 1,2,......,N. Initially, the heights of all flowers are 0.
You are given a sequence h=\{h_1,h_2,h_3,......\} as input. You would like to change the height of Flower k to h_k for all k (1 \leq k \leq N), by repeating the following "watering" operation:

Specify integers l and r. Increase the height of Flower x by 1 for all x such that l \leq x \leq r.

Find the minimum number of watering operations required to satisfy the condition.

Constraints

1 \leq N \leq 100

0 \leq h_i \leq 100

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N
h_1 h_2 h_3 ...... h_N

Output

Print the minimum number of watering operations required to satisfy the condition.

Sample Input 1

4
1 2 2 1

Sample Output 1

2

The minimum number of watering operations required is 2.
One way to achieve it is:

Perform the operation with (l,r)=(1,3).

Perform the operation with (l,r)=(2,4).

Sample Input 2

5
3 1 2 3 1

Sample Output 2

5

Sample Input 3

8
4 23 75 0 23 96 50 100

Sample Output 3

221

Solution in C++14 (GCC 5.4.1) (judge verdict: Runtime Error)

#include <cstdio>
#include <vector>
#include <algorithm>

int main(){
	char N;
	scanf("%d", &N);

	char* map[101];
	for (int i = 0; i < 101; i++) {
		map[i] = new char[N + 1];
		map[i][0] = 0;
	}

	char tmp;
	for (int i = 1; i < N + 1; i++) {
		scanf("%d", &tmp);
		for (int j = 0; j < 101; j++) {
			if (j < tmp)
				map[j][i] = 1;
			else 
				map[j][i] = 0;
		}

	}

	int count = 0;
	for (int i = 0; i < 101; i++) {
		for (int j = 0; j < N; j++) {
			if (map[i][j] == 0 && map[i][j + 1] == 1) count++;
		}
	}

	printf("%d\n", count);

	return 0;
}