Lưu ý: Các code mẫu dưới đây chỉ mang tính tham khảo và có thể không AC được bài tập này

Code mẫu của flashmt

#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cstring>
using namespace std;
const int base1 = 59, base2 = 241, N = 1000100;

char a[N], b[N];
int lenA, lenB;
long long p1[N], p2[N], hashA1[N], hashA2[N], hashB1[N], hashB2[N];

int equal(int l, int r, int ll, int rr)
{
    if ((hashA1[r] - hashA1[l - 1]) * p1[ll] != (hashB1[rr] - hashB1[ll - 1]) * p1[l]) return 0;
    if ((hashA2[r] - hashA2[l - 1]) * p2[ll] != (hashB2[rr] - hashB2[ll - 1]) * p2[l]) return 0;
    return 1;
}

char comp(int l, int r, int ll, int rr)
{
    int low = 1, high = min(r - l, rr - ll) + 1, match = 0;
    while (low <= high)
    {
        int mid = (low + high) / 2;
        if (equal(l, l + mid - 1, ll, ll + mid - 1)) match = mid, low = mid + 1;
        else high = mid - 1;
    }

    if (l + match > r && ll + match > rr) return '=';
    if (l + match > r) return '<';
    if (ll + match > rr) return '>';
    return a[l + match] < b[ll + match] ? '<' : '>';
}

int main()
{
    cin >> lenA >> lenB;
    scanf("%s%s", a + 1, b + 1);

    p1[0] = p2[0] = 1;
    for (int i = 1; i <= 1000000; i++) 
    {
        p1[i] = p1[i - 1] * base1;
        p2[i] = p2[i - 1] * base2;
    }

    for (int i = 1; i <= lenA; i++) 
    {
        hashA1[i] = hashA1[i - 1] + p1[i - 1] * (a[i] - 'a');
        hashA2[i] = hashA2[i - 1] + p2[i - 1] * (a[i] - 'a');
    }
    for (int i = 1; i <= lenB; i++) 
    {
        hashB1[i] = hashB1[i - 1] + p1[i - 1] * (b[i] - 'a');
        hashB2[i] = hashB2[i - 1] + p2[i - 1] * (b[i] - 'a');
    }

    int q, l, r, ll, rr;
    cin >> q;
    while (q--)
    {
        scanf("%d%d%d%d", &l, &r, &ll, &rr);
        printf("%c",comp(l, r, ll, rr));
    }
}

Code mẫu của ladpro98

program VOSTR;
uses    math;
const   fi='';
        maxn=trunc(1e6)+6;
        b1 = trunc(1e4)+1;
        b2 = trunc(1e4)+7;
        bb1 = b1*b1;
        bb2 = b2*b2;
var     a,b:ansistring;
        na,nb,qq,q,i,l,r,m,maxL,oa,x,y,j,ll,l1,l2:longint;
        ha1,hb1,hb2,ha2:longint;
        hashA1,hashB1,hashA2,hashB2,pow1,pow2:array[0..maxn] of longint;
        inp:text;
begin
        assign(inp,fi);reset(inp);
        readln(inp,na,nb);
        readln(inp,a);readln(inp,b);
        pow1[0]:=1;pow2[0]:=1;oa:=ord('a');
        for i:=1 to max(na,nb) do pow1[i]:=(pow1[i-1]*26) mod b1;
        for i:=1 to max(na,nb) do pow2[i]:=(pow2[i-1]*26) mod b2;
        for i:=1 to na do hashA1[i]:=(hashA1[i-1]*26+ord(a[i])-oa) mod b1;
        for i:=1 to na do hashA2[i]:=(hashA2[i-1]*26+ord(a[i])-oa) mod b2;
        for i:=1 to nb do hashB1[i]:=(hashB1[i-1]*26+ord(b[i])-oa) mod b1;
        for i:=1 to nb do hashB2[i]:=(hashB2[i-1]*26+ord(b[i])-oa) mod b2;
        readln(inp,q);
        for qq:=1 to q do begin
                readln(inp,i,j,x,y);
                l1:=j-i;l2:=y-x;
                maxL:=min(l1,l2);
                Ll:=0;l:=0;r:=maxL;
                while l<=r do begin
                        m:=(l+r) shr 1;
                        hA1:=(hashA1[i+m]-pow1[m+1]*hashA1[i-1]+bb1) mod b1;
                        hB1:=(hashB1[x+m]-pow1[m+1]*hashB1[x-1]+bb1) mod b1;
                        hA2:=(hashA2[i+m]-pow2[m+1]*hashA2[i-1]+bb2) mod b2;
                        hB2:=(hashB2[x+m]-pow2[m+1]*hashB2[x-1]+bb2) mod b2;
                        if (hA1 = hB1) and (hA2=hB2) then begin
                                Ll:=m;
                                l:=m+1;
                        end
                        else    r:=m-1;
                end;
                if Ll = maxL then begin
                        if l1=l2 then write('=') else
                        if l1<l2 then write('<') else write('>');
                end
                else begin
                        if a[i+Ll+1]<b[x+Ll+1] then write('<') else write('>');
                end;
        end;
end.

Code mẫu của RR

// VOSTR Solution by RR
// O(Q*log(N))

#include <sstream>
#include <iomanip>
#include <iostream>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#include <vector>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <string>
#include <deque>
#include <complex>
#include <fstream>

#define FOR(i,a,b) for(int i=(a),_b=(b); i<=_b; i++)
#define FORD(i,a,b) for(int i=(a),_b=(b); i>=_b; i--)
#define REP(i,a) for(int i=0,_a=(a); i<_a; i++)
#define FORN(i,a,b) for(int i=(a),_b=(b);i<_b;i++)
#define DOWN(i,a,b) for(int i=a,_b=(b);i>=_b;i--)
#define SET(a,v) memset(a,v,sizeof(a))
#define sqr(x) ((x)*(x))
#define ll long long
#define F first
#define S second
#define PB push_back
#define MP make_pair

#define DEBUG(x) cout << #x << " = "; cout << x << endl;
#define PR(a,n) cout << #a << " = "; FOR(_,1,n) cout << a[_] << ' '; cout << endl;
#define PR0(a,n) cout << #a << " = "; REP(_,n) cout << a[_] << ' '; cout << endl;
using namespace std;

//Buffer reading
int INP,AM,REACHEOF;
#define BUFSIZE (1<<12)
char BUF[BUFSIZE+1], *inp=BUF;
#define GETCHAR(INP) { \
    if(!*inp) { \
        if (REACHEOF) return 0;\
        memset(BUF,0,sizeof BUF);\
        int inpzzz = fread(BUF,1,BUFSIZE,stdin);\
        if (inpzzz != BUFSIZE) REACHEOF = true;\
        inp=BUF; \
    } \
    INP=*inp++; \
}
#define DIG(a) (((a)>='0')&&((a)<='9'))
#define GN(j) { \
    AM=0;\
    GETCHAR(INP); while(!DIG(INP) && INP!='-') GETCHAR(INP);\
    if (INP=='-') {AM=1;GETCHAR(INP);} \
    j=INP-'0'; GETCHAR(INP); \
    while(DIG(INP)){j=10*j+(INP-'0');GETCHAR(INP);} \
    if (AM) j=-j;\
}
//End of buffer reading

const long double PI = acos((long double) -1.0);
const int MN = 2000111;

int la, lb;
char a[MN], b[MN];
long long ha[MN], hb[MN], p[MN];

void init() {
    p[0] = 1;
    FOR(i,1,2000000) p[i] = p[i-1] * 31;

    FOR(i,1,la) {
        ha[i] = ha[i-1] + p[i-1] * (long long) (a[i] - 'a');
    }

    FOR(i,1,lb) {
        hb[i] = hb[i-1] + p[i-1] * (long long) (b[i] - 'a');
    }
}

bool equal(int l, int r, int u, int v) {
    long long va = ha[r] - ha[l-1];
    long long vb = hb[v] - hb[u-1];

    return va * p[u] == vb * p[l];
}

char compare(int l, int r, int u, int v) {
    int len1 = r - l + 1;
    int len2 = v - u + 1;
    int len = min(len1, len2);

    int left = 0, right = len, res = 0;

    while (left <= right) {
        int mid = (left + right) >> 1;
        if (equal(l, l+mid-1, u, u+mid-1)) {
            res = mid;
            left = mid + 1;
        }
        else right = mid - 1;
    }

    if (res == len) {
        if (len1 < len2) return '<';
        else if (len1 > len2) return '>';
        else return '=';
    }
    else {
        char ca = a[l+res];
        char cb = b[u+res];

        if (ca < cb) return '<';
        else if (ca > cb) return '>';
        else return '=';
    }
}

int main() {
    scanf("%d%d\n", &la, &lb);
    scanf("%s\n", &a[1]);
    scanf("%s\n", &b[1]);

    init();

    int q; scanf("%d", &q);
    while (q--) {
        int l,r,u,v;
        scanf("%d%d%d%d", &l, &r, &u, &v);
        putchar(compare(l, r, u, v));
    }
    puts("");
    return 0;
}

Code mẫu của hieult

#include <set>
#include <map>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <cstdlib>
#include <cstring>
#include <sstream>
#include <iomanip>
#include <iostream>
#include <algorithm>

#include <ctime>
#include <deque>
#include <bitset>
#include <cctype>
#include <utility>
#include <cassert>

using namespace std;

typedef long long ll;
typedef double ld;
typedef unsigned int ui;
typedef unsigned long long ull;

#define Rep(i,n) for(int i = 0; i < (n); ++i)
#define Repd(i,n) for(int i = (n)-1; i >= 0; --i)
#define For(i,a,b) for(int i = (a); i <= (b); ++i)
#define Ford(i,a,b) for(int i = (a); i >= (b); --i)
//#define Fit(i,v) for(__typeof((v).begin()) i = (v).begin(); i != (v).end(); ++i)
//#define Fitd(i,v) for(__typeof((v).rbegin()) i = (v).rbegin(); i != (v).rend(); ++i)
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define sz(a) ((int)(a).size())
#define all(a) (a).begin(), (a).end()
#define ms(a,x) memset(a, x, sizeof(a))

template<class F, class T> T convert(F a, int p = -1) { stringstream ss; if (p >= 0) ss << fixed << setprecision(p); ss << a; T r; ss >> r; return r; }
template<class T> T gcd(T a, T b) { T r; while (b != 0) { r = a % b; a = b; b = r; } return a; }
template<class T> T lcm(T a, T b) { return a / gcd(a, b) * b; }
template<class T> T sqr(T x) { return x * x; }
template<class T> T cube(T x) { return x * x * x; }
template<class T> int getbit(T s, int i) { return (s >> i) & 1; }
template<class T> T onbit(T s, int i) { return s | (T(1) << i); }
template<class T> T offbit(T s, int i) { return s & (~(T(1) << i)); }
template<class T> int cntbit(T s) { return s == 0 ? 0 : cntbit(s >> 1) + (s & 1); }

const int bfsz = 1 << 16;
char bf[bfsz + 5];
int rsz = 0;
int ptr = 0;
char gc() {
    if (rsz <= 0) {
        ptr = 0;
        rsz = (int) fread(bf, 1, bfsz, stdin);
        if (rsz <= 0)
            return EOF;
    }
    --rsz;
    return bf[ptr++];
}
void ga(char &c) {
    c = EOF;
    while (!isalpha(c))
        c = gc();
}
int gs(char s[]) {
    int l = 0;
    char c = gc();
    while (isspace(c))
        c = gc();
    while (c != EOF && !isspace(c)) {
        s[l++] = c;
        c = gc();
    }
    s[l] = '\0';
    return l;
}
template<class T> bool gi(T &v) {
    v = 0;
    char c = gc();
    while (c != EOF && c != '-' && !isdigit(c))
        c = gc();
    if (c == EOF)
        return false;
    bool neg = c == '-';
    if (neg)
        c = gc();
    while (isdigit(c)) {
        v = v * 10 + c - '0';
        c = gc();
    }
    if (neg)
        v = -v;
    return true;
}

typedef pair<int, int> II;

const ld PI = acos(-1.0);
const ld eps = 1e-9;

const int dr[] = {0, +1, 0, -1};
const int dc[] = {+1, 0, -1, 0};

const int inf = (int)1e9 + 5;
const ll linf = (ll)1e16 + 5;
const ll mod = (ll)1e9 + 7;

#define maxn 1000005

char s1[maxn], s2[maxn], res[maxn];
int n, m, q;
ll f1[maxn], f2[maxn], mu[maxn];
ll F1[maxn], F2[maxn], Mu[maxn];

bool cal(int l1, int r1, int l2, int r2){
    return f1[r1] - f1[l1 - 1] * mu[r1 - l1 + 1] == f2[r2] - f2[l2 - 1] * mu[r2 - l2 + 1];
//      && (F1[r1] - F1[l1 - 1] * Mu[r1 - l1 + 1] - (F2[r2] - F2[l2 - 1] * Mu[r2 - l2 + 1])) % mod == 0;
}

int  main()
{
//  freopen("in.txt", "r", stdin);
    cin >> n >> m;
    scanf("%s %s", s1, s2);
    f1[0] = 0; f2[0] = 0; F1[0] = 0; F2[0] = 0;
    mu[0] = 1;
    Mu[0] = 1;
    Rep(i, maxn - 1) {
        mu[i + 1] = mu[i] * mod;
        Mu[i + 1] = Mu[i] * inf % mod;
    }
    Rep(i, n) {
        f1[i + 1] = f1[i] * mod + s1[i];
        F1[i + 1] = (F1[i] * inf + s1[i]) % mod;
    }
    Rep(i, m) {
        f2[i + 1] = f2[i] * mod + s2[i];
        F2[i + 1] = (F2[i] * inf + s2[i]) % mod;
    }

    cin >> q;
    int l1, r1, l2, r2, l, r, mid;
    Rep(i, q){
        scanf("%d %d %d %d", &l1, &r1, &l2, &r2);
        l = 1; r = min(r1 - l1, r2 - l2) + 2;
        while(l < r){
            mid = (l + r) >> 1;
            if(cal(l1, l1 + mid - 1, l2, l2 + mid - 1)){
                l = mid + 1;
            }
            else r = mid;
        }
        if(l == min(r1 - l1, r2 - l2) + 2){
            if(r1 - l1 == r2 - l2) res[i] = '=';
            else if(r1 - l1 < r2 - l2) res[i] = '<';
            else res[i] = '>';
        }
        else{
            if(s1[l1 + l - 2] < s2[l2 + l - 2]) res[i] = '<';
            else res[i] = '>';
        }
    }

    res[q] = '\0';
    printf("%s", res);
}