You wrote down many positive integers in a string called num
. However, you realized that you forgot to add commas to seperate the different numbers. You remember that the list of integers was non-decreasing and that no integer had leading zeros.
Return the number of possible lists of integers that you could have written down to get the string num
. Since the answer may be large, return it modulo 109 + 7
.
Example 1:
Input: num = "327" Output: 2 Explanation: You could have written down the numbers: 3, 27 327
Example 2:
Input: num = "094" Output: 0 Explanation: No numbers can have leading zeros and all numbers must be positive.
Example 3:
Input: num = "0" Output: 0 Explanation: No numbers can have leading zeros and all numbers must be positive.
Constraints:
1 <= num.length <= 3500
num
consists of digits'0'
through'9'
.
class Solution:
def numberOfCombinations(self, num: str) -> int:
def cmp(i, j, k):
x = lcp[i][j]
return x >= k or num[i + x] >= num[j + x]
mod = 10**9 + 7
n = len(num)
lcp = [[0] * (n + 1) for _ in range(n + 1)]
for i in range(n - 1, -1, -1):
for j in range(n - 1, -1, -1):
if num[i] == num[j]:
lcp[i][j] = 1 + lcp[i + 1][j + 1]
dp = [[0] * (n + 1) for _ in range(n + 1)]
dp[0][0] = 1
for i in range(1, n + 1):
for j in range(1, i + 1):
v = 0
if num[i - j] != '0':
if i - j - j >= 0 and cmp(i - j, i - j - j, j):
v = dp[i - j][j]
else:
v = dp[i - j][min(j - 1, i - j)]
dp[i][j] = (dp[i][j - 1] + v) % mod
return dp[n][n]
class Solution {
private static final int MOD = (int) 1e9 + 7;
public int numberOfCombinations(String num) {
int n = num.length();
int[][] lcp = new int[n + 1][n + 1];
for (int i = n - 1; i >= 0; --i) {
for (int j = n - 1; j >= 0; --j) {
if (num.charAt(i) == num.charAt(j)) {
lcp[i][j] = 1 + lcp[i + 1][j + 1];
}
}
}
int[][] dp = new int[n + 1][n + 1];
dp[0][0] = 1;
for (int i = 1; i <= n; ++i) {
for (int j = 1; j <= i; ++j) {
int v = 0;
if (num.charAt(i - j) != '0') {
if (i - j - j >= 0) {
int x = lcp[i - j][i - j - j];
if (x >= j || num.charAt(i - j + x) >= num.charAt(i - j - j + x)) {
v = dp[i - j][j];
}
}
if (v == 0) {
v = dp[i - j][Math.min(j - 1, i - j)];
}
}
dp[i][j] = (dp[i][j - 1] + v) % MOD;
}
}
return dp[n][n];
}
}
class Solution {
public:
const int mod = 1e9 + 7;
int numberOfCombinations(string num) {
int n = num.size();
vector<vector<int>> lcp(n + 1, vector<int>(n + 1));
for (int i = n - 1; i >= 0; --i) {
for (int j = n - 1; j >= 0; --j) {
if (num[i] == num[j]) {
lcp[i][j] = 1 + lcp[i + 1][j + 1];
}
}
}
auto cmp = [&](int i, int j, int k) {
int x = lcp[i][j];
return x >= k || num[i + x] >= num[j + x];
};
vector<vector<int>> dp(n + 1, vector<int>(n + 1));
dp[0][0] = 1;
for (int i = 1; i <= n; ++i) {
for (int j = 1; j <= i; ++j) {
int v = 0;
if (num[i - j] != '0') {
if (i - j - j >= 0 && cmp(i - j, i - j - j, j)) {
v = dp[i - j][j];
} else {
v = dp[i - j][min(j - 1, i - j)];
}
}
dp[i][j] = (dp[i][j - 1] + v) % mod;
}
}
return dp[n][n];
}
};
func numberOfCombinations(num string) int {
n := len(num)
lcp := make([][]int, n+1)
dp := make([][]int, n+1)
for i := range lcp {
lcp[i] = make([]int, n+1)
dp[i] = make([]int, n+1)
}
for i := n - 1; i >= 0; i-- {
for j := n - 1; j >= 0; j-- {
if num[i] == num[j] {
lcp[i][j] = 1 + lcp[i+1][j+1]
}
}
}
cmp := func(i, j, k int) bool {
x := lcp[i][j]
return x >= k || num[i+x] >= num[j+x]
}
dp[0][0] = 1
var mod int = 1e9 + 7
for i := 1; i <= n; i++ {
for j := 1; j <= i; j++ {
v := 0
if num[i-j] != '0' {
if i-j-j >= 0 && cmp(i-j, i-j-j, j) {
v = dp[i-j][j]
} else {
v = dp[i-j][min(j-1, i-j)]
}
}
dp[i][j] = (dp[i][j-1] + v) % mod
}
}
return dp[n][n]
}
func min(a, b int) int {
if a < b {
return a
}
return b
}