add (programmers - level1, 3 각 1문제): js 풀이

programmers/level1/모의고사.js

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+function solution(answers) {
+  var answer = [];
+
+  // 1번: 1, 2, 3, 4, 5,
+  //      6, 7, 8, 9, 10
+  // 2번: 2, 1, 2, 3, 2, 4, 2, 5
+  // a[0] = p2[0] 0 % 7 = 0
+  // a[1] = p2[1] 1 % 7 = 1
+  // a[8] = p2[0] 8 % 7 = 1 - 1
+  // 3번: 3, 3, 1, 1, 2, 2, 4, 4, 5, 5
+  // a[0] = p3[0] = 0 & 9 = 0
+  // a[1] = p3[1] = 1 % 9 = 1
+
+  // a[10] = p3[0] 10 % 9 - 1
+  // a[11] = p3[1] 11 % 9 = 2 - 1 = 1
+  // a[12] = p3[2] 12 % 9 = 3 - 1 = 2
+
+  const p2 = [2, 1, 2, 3, 2, 4, 2, 5];
+  const p3 = [3, 3, 1, 1, 2, 2, 4, 4, 5, 5];
+
+  const corrects = [0, 0, 0];
+
+  answers.forEach((ans, idx) => {
+    if (ans === (idx % 5) + 1) {
+      corrects[0] = corrects[0] + 1;
+    }
+
+    if (ans === p2[idx % 8]) {
+      corrects[1] = corrects[1] + 1;
+    }
+
+    if (ans === p3[idx % 10]) {
+      corrects[2] = corrects[2] + 1;
+    }
+  });
+
+  const max = Math.max(...corrects);
+
+  corrects.forEach((c, i) => {
+    if (c === max) {
+      answer.push(i + 1);
+    }
+  });
+
+  return answer;
+}
+
+function solution2(answers) {
+  let answer = [];
+
+  const num1 = [1, 2, 3, 4, 5];
+  const num2 = [2, 1, 2, 3, 2, 4, 2, 5];
+  const num3 = [3, 3, 1, 1, 2, 2, 4, 4, 5, 5];
+
+  const score = new Map();
+  score.set(1, 0);
+  score.set(2, 0);
+  score.set(3, 0);
+
+  answers.forEach((ans, idx) => {
+    if (num1[idx % 5] === ans) {
+      score.set(1, score.get(1) + 1);
+    }
+
+    if (num2[idx % 8] === ans) {
+      score.set(2, score.get(2) + 1);
+    }
+
+    if (num3[idx % 10] === ans) {
+      score.set(3, score.get(3) + 1);
+    }
+  });
+
+  const max = Math.max(...score.values());
+
+  for (const [key, value] of score.entries()) {
+    if (value === max) {
+      answer.push(key);
+    }
+  }
+  return answer;
+}

programmers/level3/단속카메라.js

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+function solution(routes) {
+  let answer = 0;
+
+  routes.sort((a, b) => {
+    if (a[0] !== b[0]) {
+      return a[0] - b[0];
+    } else {
+      a[1] - b[1];
+    }
+  });
+
+  let prev = Number.NEGATIVE_INFINITY;
+  for (const route of routes) {
+    const [start, end] = route;
+
+    if (prev < start) {
+      answer++;
+      prev = end;
+      continue;
+    }
+
+    if (prev > end) {
+      prev = end;
+    }
+  }
+  return answer;
+}