題意

求 \(\ a_0+a_1x+a_2x^{2+\cdots+a_nx}n=0\)在[1,m]區間的整數解

題解

用秦九昭公式，暴力即可

除錯記錄

為了防止爆long long，要模一個較大的質數

#include <cstdio>
#include <cctype>
#define int long long
#define maxn 105
#define mo 1000000007

using namespace std;

int n, m, a[maxn], ans[maxn];

void read(int &x){
    int opt =
 
 1; char ch = getchar();
    while (!isdigit(ch)){ if (ch == '-') opt = -1; ch = getchar(); }
    while (isdigit(ch)) x = (x * 10 + (ch & 15)) % mo, ch = getchar();
    x *= opt;
}

signed main(){
    read(n), read(m);
    
    for (int i = 0; i <= n; i++){
        read(a[i]);
    }
    
    for
 
 (int i = 1; i <= m; i++){
        int sum = a[n];
        for (int j = n - 1; j >= 0; j--)
            ((sum *= i) += a[j]) %= mo;
        if (sum == 0) ans[++ans[0]] = i;
    }
    
    printf("%lld\n", ans[0]);
    for (int i = 1; i <= ans[0]; i++) printf("%lld\n", ans[i]);
    
    return 0;
}