コード
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.NoSuchElementException;
public class Main {
private static class Task {
private final int MOD = (int) 1e9 + 7;
long modPow(long x, long e) {
long ret = 1;
long cur = x;
while (e > 0) {
if ((e & 1) != 0) ret = (ret * cur) % MOD;
cur = (cur * cur) % MOD;
e /= 2;
}
return ret;
}
void solve(FastScanner in, PrintWriter out) {
int N = in.nextInt();
int C = in.nextInt();
int[] A = in.nextIntArray(N);
int[] B = in.nextIntArray(N);
long[][] sum = new long[401][C + 1];
for (int x = 0; x <= 400; x++) {
for (int k = 0; k <= C; k++) {
sum[x][k] = modPow(x, k);
}
}
for (int k = 0; k <= C; k++) {
for (int i = 0; i < 400; i++) {
sum[i + 1][k] += sum[i][k];
sum[i + 1][k] %= MOD;
}
}
long[][] dp = new long[N + 1][C + 1];
dp[0][0] = 1;
for (int i = 0; i < N; i++) {
for (int j = 0; j <= C; j++) {
long d = 0;
for (int k = 0; k <= j; k++) {
d += dp[i][j - k] * ((sum[B[i]][k] - sum[A[i] - 1][k] + MOD) % MOD);
d %= MOD;
}
dp[i + 1][j] = d;
}
}
out.println(dp[N][C]);
}
}
ここから下はテンプレートです。
public static void main(String[] args) {
OutputStream outputStream = System.out;
FastScanner in = new FastScanner();
PrintWriter out = new PrintWriter(outputStream);
Task solver = new Task();
solver.solve(in, out);
out.close();
}
private static class FastScanner {
private final InputStream in = System.in;
private final byte[] buffer = new byte[1024];
private int ptr = 0;
private int bufferLength = 0;
private boolean hasNextByte() {
if (ptr < bufferLength) {
return true;
} else {
ptr = 0;
try {
bufferLength = in.read(buffer);
} catch (IOException e) {
e.printStackTrace();
}
if (bufferLength <= 0) {
return false;
}
}
return true;
}
private int readByte() {
if (hasNextByte()) return buffer[ptr++];
else return -1;
}
private static boolean isPrintableChar(int c) {
return 33 <= c && c <= 126;
}
private void skipUnprintable() {
while (hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++;
}
boolean hasNext() {
skipUnprintable();
return hasNextByte();
}
public String next() {
if (!hasNext()) throw new NoSuchElementException();
StringBuilder sb = new StringBuilder();
int b = readByte();
while (isPrintableChar(b)) {
sb.appendCodePoint(b);
b = readByte();
}
return sb.toString();
}
long nextLong() {
if (!hasNext()) throw new NoSuchElementException();
long n = 0;
boolean minus = false;
int b = readByte();
if (b == '-') {
minus = true;
b = readByte();
}
if (b < '0' || '9' < b) {
throw new NumberFormatException();
}
while (true) {
if ('0' <= b && b <= '9') {
n *= 10;
n += b - '0';
} else if (b == -1 || !isPrintableChar(b)) {
return minus ? -n : n;
} else {
throw new NumberFormatException();
}
b = readByte();
}
}
double nextDouble() {
return Double.parseDouble(next());
}
double[] nextDoubleArray(int n) {
double[] array = new double[n];
for (int i = 0; i < n; i++) {
array[i] = nextDouble();
}
return array;
}
double[][] nextDoubleMap(int n, int m) {
double[][] map = new double[n][];
for (int i = 0; i < n; i++) {
map[i] = nextDoubleArray(m);
}
return map;
}
public int nextInt() {
return (int) nextLong();
}
public int[] nextIntArray(int n) {
int[] array = new int[n];
for (int i = 0; i < n; i++) array[i] = nextInt();
return array;
}
public long[] nextLongArray(int n) {
long[] array = new long[n];
for (int i = 0; i < n; i++) array[i] = nextLong();
return array;
}
public String[] nextStringArray(int n) {
String[] array = new String[n];
for (int i = 0; i < n; i++) array[i] = next();
return array;
}
public char[][] nextCharMap(int n) {
char[][] array = new char[n][];
for (int i = 0; i < n; i++) array[i] = next().toCharArray();
return array;
}
}
}