Number of People Aware of a Secret - Problem

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int max(int a, int b) {
    return a > b ? a : b;
}

int solution(int n, int delay, int forget) {
    const int MOD = 1000000007;
    long long dp[1001];
    memset(dp, 0, sizeof(dp));
    dp[1] = 1;
    
    long long share = 0;
    
    for (int i = 2; i <= n; i++) {
        if (i - delay >= 1) {
            share = (share + dp[i - delay]) % MOD;
        }
        
        if (i - forget >= 1) {
            share = (share - dp[i - forget] + MOD) % MOD;
        }
        
        dp[i] = share;
    }
    
    long long result = 0;
    for (int i = max(1, n - forget + 1); i <= n; i++) {
        result = (result + dp[i]) % MOD;
    }
    
    return (int) result;
}

int main() {
    int n, delay, forget;
    scanf("%d", &n);
    scanf("%d", &delay);
    scanf("%d", &forget);
    
    int result = solution(n, delay, forget);
    printf("%d\n", result);
    
    return 0;
}