365天挑战LeetCode1000题——Day 088 最大交换 跳跃游戏 III 到家的最少跳跃次数 水壶问题

670. 最大交换

代码实现

class Solution {
public:
    int maximumSwap(int num) {
        if (num < 10) return num;
        int tmp = num;
        vector<int> arr;
        while (tmp) {
            arr.insert(arr.begin(), tmp % 10);
            tmp /= 10;
        }
        vector<int> tmp1 = arr;
        sort(tmp1.begin(), tmp1.end(), greater<int>());
        int i = 0;
        for (; i < arr.size(); i++) {
            if (tmp1[i] != arr[i]) break;
        }
        if (i == arr.size()) return num;
        int j = i;
        int sub = j, maxNum = 0;
        // cout << i;
        for (; i < arr.size(); i++) {
            if (arr[i] >= maxNum) {
                maxNum = arr[i];
                sub = i;
            }
        }
        // cout << endl;
        // cout << sub;
        swap(arr[j], arr[sub]);
        int ans = 0;
        for (int i = 0; i < arr.size(); i++) {
            ans = ans * 10 + arr[i];
        }
        return ans;
    }
};
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1306. 跳跃游戏 III

代码实现

class Solution {
public:
    bool canReach(vector<int>& arr, int start) {
        int n = arr.size();
        vector<bool> visited(n, false);
        queue<int> myQueue;
        myQueue.push(start);
        int tmp;
        while (!myQueue.empty()) {
            tmp = myQueue.front();
            myQueue.pop();
            if (visited[tmp]) continue;
            visited[tmp] = true;
            if (!arr[tmp]) return true;
            if (tmp + arr[tmp] < n) myQueue.push(tmp + arr[tmp]);
            if (tmp - arr[tmp] >= 0) myQueue.push(tmp - arr[tmp]);
        }
        return false;
    }
};
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1654. 到家的最少跳跃次数

代码实现

class Solution {
public:
    int minimumJumps(vector<int>& forbidden, int a, int b, int x) {
        queue<pair<int, int>> myQueue;
        set<int> f;
        for (auto & b : forbidden) {
            f.emplace(b);
        }
        set<pair<int, int>> visited;
        myQueue.push({x, 0});
        int t = 0;
        while (!myQueue.empty()) {
            int sz = myQueue.size();
            while (sz--) {
                auto [loc, time] = myQueue.front();
                // cout << loc << " " << time << endl;
                myQueue.pop();
                if (loc == 0) return t;
                if (f.count(loc) || visited.count(make_pair(loc, time))) continue;
                visited.emplace(make_pair(loc, time));
                if (loc < 0) continue;
                if (loc > 6000) continue;
                myQueue.push({loc - a, 0});
                if (!time) myQueue.push({loc + b, 1});
            }
            t++;
        }
        return -1;
    }
};
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365. 水壶问题

代码实现

class Solution {
public:
    bool canMeasureWater(int x, int y, int z) {
        if (x + y < z) return false;
        if (x == 0 || y == 0) return z == 0 || (x + y) == z;
        return z % gcd(x, y) == 0;
    }
};
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