【Codeforces 364A】Matrix
【链接】 我是链接,点我呀:)
【题意】
【题解】
(x,y,z,t) 会发现它的和就是sum(x,y)*sum(z,t) sum(x,y)=a[x]+a[x+1]+...+a[y] 因为这个子矩阵的和就是 a[x][z]+a[x][z+1]+...+a[x][t] + a[x+1][z] + a[x+1][z+1]....+a[x+1][t] .... 而a[i][j] = a[i]*a[j] 下次遇到这样的就动手算一算和是什么 看看能不能找出规律 注意a=0的时候的情况分类讨论一波 sum(x,y)最多就为9*|s| 因此如果a/i >9*|s|就不用管它【代码】
import java.io.*;
import java.util.*;
public class Main {
static InputReader in;
static PrintWriter out;
public static void main(String[] args) throws IOException{
//InputStream ins = new FileInputStream("E:\\rush.txt");
InputStream ins = System.in;
in = new InputReader(ins);
out = new PrintWriter(System.out);
//code start from here
new Task().solve(in, out);
out.close();
}
static int N = 4000;
static class Task{
int cnt[] = new int[N*10+100];
int s[] = new int[N+10];
String S;
int a,n;
public void solve(InputReader in,PrintWriter out) {
a = in.nextInt();
S = in.next();
for (int i = 0;i < (int)S.length();i++) {
s[i+1] = S.charAt(i)-'0';
}
n = S.length();
for (int i = 1;i <= n;i++) {
int temp = 0;
for (int j = i;j <= n;j++) {
temp = temp + s[j];
cnt[temp]++;
}
}
long ans = 0;
if (a==0) {
//a==0
//sum(x,y)*sum(z,t)==0
//sum(x,y)==0 sum(z,t)!=0
//or sum(x,y)!=0 sum(z,t)==0
for (int i = 1;i <=N*10;i++) {
ans = ans + 1l*2*cnt[0]*cnt[i];
}
//sum(x,y)==0 sum(z,t)==0
ans = ans + 1l*cnt[0]*cnt[0];
}else {
for (int i = 1;i <= N*10;i++) {
if (a%i==0 && a/i<=(N*10)) {
ans = ans + 1l*cnt[i]*cnt[a/i];
}
}
}
out.println(ans);
}
}
static class InputReader{
public BufferedReader br;
public StringTokenizer tokenizer;
public InputReader(InputStream ins) {
br = new BufferedReader(new InputStreamReader(ins));
tokenizer = null;
}
public String next(){
while (tokenizer==null || !tokenizer.hasMoreTokens()) {
try {
tokenizer = new StringTokenizer(br.readLine());
}catch(IOException e) {
throw new RuntimeException(e);
}
}
return tokenizer.nextToken();
}
public int nextInt() {
return Integer.parseInt(next());
}
}
}