/*
* Author: Arpit Bhayani
* https://arpitbhayani.me
*/
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <climits>
#include <deque>
#include <iostream>
#include <list>
#include <limits>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <vector>
#define ll long long
#define MIN(a, b) a < b ? a : b
#define MAX(a, b) a > b ? a : b
using namespace std;
int readline(char *str) {
int i = 0;
char ch;
while((ch = getchar()) != '\n') {
str[i++] = ch;
}
str[i] = '\0';
return i;
}
int main(int argc, char *argv[]) {
int n;
scanf("%d", &n);
int *arr = (int *) calloc(n, sizeof(int));
int *jumps = (int *) calloc(n, sizeof(int));
for(int i = 0 ; i < n; i++) {
scanf("%d", &arr[i]);
jumps[i] = 0;
}
jumps[0] = 0;
jumps[1] = (arr[1] == 1) ? 0 : jumps[0] + 1;
for(int i = 2 ; i < n ; i++) {
int first = i - 1;
int second = i - 2;
if(arr[second] == 1) {
jumps[i] = jumps[first] + 1;
}
else {
jumps[i] = jumps[second] + 1;
}
}
printf("%d\n", jumps[n-1]);
free(arr);
return 0;
}
System Design for Beginners
A masterclass that helps early engineers and product managers become great at designing scalable systems.
180+ learners
Details →System Design Masterclass
A masterclass that helps you become great at designing scalable, fault-tolerant, and highly available systems.
1000+ learners
Details →Redis Internals
Learn internals of Redis by re-implementing some of the core features in Golang.
98+ learners
Details →