911G - Mass Change Queries - CodeForces Solution

#pragma GCC optimize("Ofast")
#pragma GCC optimize ("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
# include <iostream>
# include <stdio.h>
using namespace std;

unsigned char a[200000];

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    int n;
    scanf("%d", &n);
    for (int i = 0; i < n; ++i) {
        scanf("%hhu", &a[i]);
    }
    int q;
    scanf("%d", &q);
    while (q--) {
        int l, r;
        unsigned char x, y;
        scanf("%d%d%hhu%hhu", &l, &r, &x, &y);
        for (int i = l-1; i < r; i++) {
            a[i] = a[i] == x ? y : a[i];
        }
    }
    for (int i = 0; i < n; ++i) {
        printf("%hhu ", a[i]);
    }
}
//O(n^2) test... it seems possible for this... but it shoudnt...