Leetcode在線編程 integer-to-roman

Leetcode在線編程 integer-to-roman

題目鏈接

integer-to-roman

題目描述

Given an integer, convert it to a roman numeral.
Input is guaranteed to be within the range from 1 to 3999.

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題意

將給定的數字轉換成羅馬數字[1,3999]

解題思路

羅馬數字通過
基本字符
I :1
V:5
X:10
L:50
C:100
D:500
M:1000

1）相同的數字連寫、所表示的數等於這些數字相加得到的數、如：Ⅲ=3；
2）小的數字在大的數字的右邊、所表示的數等於這些數字相加得到的數、 如：Ⅷ=8、Ⅻ=12；
3）小的數字、（限於 Ⅰ、X 和 C）在大的數字的左邊、所表示的數等於大數減小數得到的數、如：Ⅳ=4、Ⅸ=9；
4）正常使用時、連寫的數字重複不得超過三次；
5）在一個數的上面畫一條橫線、表示這個數擴大 1000 倍。
剩下來就簡單了，通過數組存儲個位數，十位數，百位數，千位數，便可以了

AC代碼

class Solution {
public:
    string intToRoman(int num) {
        string tmp;
        char one[][10]={"I","II","III","IV","V","VI","VII","VIII","IX"};
        char ten[][10]={"X","XX","XXX","XL","L","LX","LXX","LXXX","XC"};
        char hundred[][10]={"C","CC","CCC","CD","D","DC","DCC","DCCC","CM"};
        char thousand[][10]={"M","MM","MMM"};
        int cnt = num/1000;
        num -= cnt*1000;
        if(cnt>=1)
            tmp+=thousand[cnt-1];
        cnt = num/100;
        num -= cnt*100;
        if(cnt>=1)
            tmp+=hundred[cnt-1];
        cnt = num/10;
        num -= cnt*10;
        if(cnt>=1)
            tmp+=ten[cnt-1];
        if(num>=1)
            tmp+=one[num-1];
        return tmp ;
    }
};