|
| 1 | +/** |
| 2 | + *@param {string} s |
| 3 | + *@return {number} |
| 4 | + */ |
| 5 | +varromanToInt=function(s){ |
| 6 | +letromans={ |
| 7 | +I:1, |
| 8 | +V:5, |
| 9 | +X:10, |
| 10 | +L:50, |
| 11 | +C:100, |
| 12 | +D:500, |
| 13 | +M:1000, |
| 14 | +}; |
| 15 | + |
| 16 | +letarr=s.split(""); |
| 17 | + |
| 18 | +letsum=0; |
| 19 | + |
| 20 | +for(leti=arr.length-1;i>=0;i--){ |
| 21 | +// IV : 4 |
| 22 | +if(romans[arr[i]]===romans["V"]){ |
| 23 | +if(romans[arr[i-1]]===romans["I"]){ |
| 24 | +sum-=1*2; |
| 25 | +} |
| 26 | +} |
| 27 | +// IX : 4 |
| 28 | +if(romans[arr[i]]===romans["X"]){ |
| 29 | +if(romans[arr[i-1]]===romans["I"]){ |
| 30 | +sum-=1*2; |
| 31 | +} |
| 32 | +} |
| 33 | +// XL : 40 |
| 34 | +if(romans[arr[i]]===romans["L"]){ |
| 35 | +if(romans[arr[i-1]]===romans["X"]){ |
| 36 | +sum-=10*2; |
| 37 | +} |
| 38 | +} |
| 39 | +// XC : 90 |
| 40 | +if(romans[arr[i]]===romans["C"]){ |
| 41 | +if(romans[arr[i-1]]===romans["X"]){ |
| 42 | +sum-=10*2; |
| 43 | +} |
| 44 | +} |
| 45 | +// CD : 400 |
| 46 | +if(romans[arr[i]]===romans["D"]){ |
| 47 | +if(romans[arr[i-1]]===romans["C"]){ |
| 48 | +sum-=100*2; |
| 49 | +} |
| 50 | +} |
| 51 | +// CM : 900 |
| 52 | +if(romans[arr[i]]===romans["M"]){ |
| 53 | +if(romans[arr[i-1]]===romans["C"]){ |
| 54 | +sum-=100*2; |
| 55 | +} |
| 56 | +} |
| 57 | + |
| 58 | +sum+=romans[arr[i]]; |
| 59 | +} |
| 60 | + |
| 61 | +returnsum; |
| 62 | +}; |
| 63 | + |
| 64 | +// Runtime: 148 ms, faster than 80.16% of JavaScript online submissions for Roman to Integer. |
| 65 | +// Memory Usage: 47.5 MB, less than 18.15% of JavaScript online submissions for Roman to Integer. |