Linear Gimmick

input/code.cpp: In function 'int main()':
input/code.cpp:13:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < s.size(); ++i) {
                               ^

#include <iostream>
#include <set>
using namespace std;
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n;
    cin>>n;
    string s;
    cin>>s;
    int a = 0;
    int b = 0;
    for(int i = 0; i < s.size(); ++i) {
        if(s[i] != '<') break;
        ++a;
    }
    for(int i = (int)s.size()-1; i >= 0; --i) {
        if(s[i] != '>') break;
        ++b;
    }
    int lo = 0;
    int hi = n-1;
    int best = 0;
    while(lo <= hi) {
        int mid = (lo+hi)/2;
        set<int> st;
        for(int i = 0; i < n; ++i) {
            st.insert(st.end(), i);
        }
        int pos = mid;
        int moves = 0;
        int pois = 0;
        while(1) {
            st.erase(pos);
            ++moves;
            if(st.size() == 0) {
                cout<<n<<endl;
                return 0;
            }
            if(s[pos] ==  '<') {
                auto x = st.lower_bound(pos);
                if(x == st.begin()) {
                    pos = 0;
                    break;
                }
                --x;
                pos = *x;
            }
            else {
                auto x = st.lower_bound(pos);
                if(x == st.end()) {
                    pois = 1;
                    break;
                }
                pos = *x;
            }
        }
        best = max(moves, best);
        if(pois == 0) {
            lo = mid+1;
        }
        else {
            hi = mid-1;
        }
    }
    cout<<best<<endl;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED

Test 24

Verdict: ACCEPTED

Test 25

Verdict: ACCEPTED

Test 26

Verdict: ACCEPTED

Test 27

Verdict: ACCEPTED

Test 28

Verdict: ACCEPTED

Test 29

Verdict: ACCEPTED