70B - Text Messaging - CodeForces Solution

#include<bits/stdc++.h>
using namespace std;
int n;
char s[11451];
int main(){
	memset(s, 0, sizeof(s));
	cin >> n;
	gets(s);
	gets(s);
	int ans, size; ans = size = 0;
	for(int i = 0; s[i];){
		int j = i;
		while(s[j] != '.' && s[j] != '!' && s[j] != '?') j++;
		j++;
		if(size+j-i > n){
			size = 0;
			ans++;
			if(s[i] == ' ') i++;
		}
		size += j-i;
		if(size > n){
			cout << "Impossible";
			return 0;
		}
		i = j;
	}
	if(size != 0) ans++;
	cout << ans;
	return 0;
}