题目:
题解:
cpp
class Solution {
public:
int nthUglyNumber(int n) {
vector<int> dp(n + 1);
dp[1] = 1;
int p2 = 1, p3 = 1, p5 = 1;
for (int i = 2; i <= n; i++) {
int num2 = dp[p2] * 2, num3 = dp[p3] * 3, num5 = dp[p5] * 5;
dp[i] = min(min(num2, num3), num5);
if (dp[i] == num2) {
p2++;
}
if (dp[i] == num3) {
p3++;
}
if (dp[i] == num5) {
p5++;
}
}
return dp[n];
}
};