[LeetCode12]Integer to Roman

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Given an integer, convert it to a roman numeral.

Input is guaranteed to be within the range from 1 to 3999.

Analysis:

The key point is how to handle every digit.

1<=digit<=3

digit=4

digit =5

5<digit<=8

digit = 9

Java

public String intToRoman(int num) {        // IMPORTANT: Please reset any member data you declared, as        // the same Solution instance will be reused for each test case.        String[] symbol ={"I","V","X","L","C","D","M"};        String roman="";        int scale = 1000;        for(int i=6;i>=0;i-=2){        int digit = num/scale;        if(digit!=0){        if(digit<=3)        while((digit--)>0)        roman+=symbol[i];        else if(digit == 4){        roman+=symbol[i];        roman+=symbol[i+1];        }        else if(digit ==5)        roman+=symbol[i+1];        else if(digit <=8){        roman+=symbol[i+1];        while(((digit--)-5)>0)        roman+=symbol[i];        }        else if(digit ==9){        roman+=symbol[i];        roman+=symbol[i+2];        }                }        num = num%scale;        scale/=10;        }        return roman;    }

c++

string intToRoman(int num) {    char symbol[7] = {'I','V','X','L','C','D','M'};    string roman;    int scale = 1000;    for(int i=6;i>=0;i-=2){        int digit = num/scale;        if(digit!=0){            if(digit<=3){                roman.append(digit,symbol[i]);            }else if(digit == 4){                roman.append(1,symbol[i]);                roman.append(1,symbol[i+1]);            }else if(digit == 5){                roman.append(1,symbol[i+1]);            }else if(digit<=8){                roman.append(1,symbol[i+1]);                roman.append(digit-5,symbol[i]);            }else if(digit == 9){                roman.append(1,symbol[i]);                roman.append(1,symbol[i+2]);            }        }        num = num%scale;        scale /=10;    }    return roman;    }

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