@@ -0,0 +1,23 @@
+const [[N],[sx,sy],...points] = require('fs').readFileSync(process.platform === 'linux' ? '/dev/stdin' : require('path').resolve(__dirname,'../../../testcase.txt'))
+    .toString()
+    .trim()
+    .split('\n')
+    .map(row=>row.split(' ').map(Number))
+
+function outerProduct(v1,v2){
+    return v1[0]*v2[1] - v1[1]*v2[0]
+}
+
+let result = 0
+points.unshift([sx,sy])
+points.push([sx,sy])
+for(let i=0;i<points.length-1;i++){
+    const v1 = [points[i][0], points[i][1]]
+    const v2 = [points[i+1][0], points[i+1][1]]
+    result += outerProduct(v1,v2)
+}
+console.log(Math.abs(result/2).toFixed(1))
+
+// 00:09:50 틀렸습니다(2%) -> 선을 긋는 순서대로 좌표를 찍어야함 -> 순서대로 주어짐 -> toFixed 수정
+// 00:27:16 틀렸습니다(2%) -> 수동으로 반올림 구현
+// 00:52:29 맞았습니다(책 참고)