120. Triangle 以及一个多维vector如何初始化

1.刚开始result的初始化写的是vector<vector<int>> result,然后再去对result[0][0] = triangle[0][0]赋值，一直报错。老问题了！

2.多维vector的初始化：

vector<vector<int>> result(height,vector<int>(width))

class Solution {
public:
    int minimumTotal(vector<vector<int>>& triangle) {
        int height = triangle.size();
        if(height <= )
            return ;
        if(height == )
            return triangle[][];
        int width = triangle[height-].size();
        vector<vector<int>> result(height,vector<int>(width));
        result[][] = triangle[][];
        for(int i = ;i < height;i++){
            width = triangle[i].size();
            for(int j = ;j < width;j++){
                if(j != && j != (width-)){
                    result[i][j] = min(result[i-][j] + triangle[i][j],result[i-][j-] + triangle[i][j]);
                }
                else if(j == )
                    result[i][j] = result[i-][j] + triangle[i][j];
                else
                    result[i][j] = result[i-][j-] + triangle[i][j];
            }
        }
        int min_num = 0x7fffffff;
        for(int i = ;i < triangle[height-].size();i++){
            if(min_num > result[height-][i])
                min_num = result[height-][i];
        }
        return min_num;
    }
};

简化版

class Solution {
public:
    int minimumTotal(vector<vector<int>>& triangle) {
        int length = triangle.size();
        vector<vector<int>> result(length,vector<int>(length));
        result[][] = triangle[][];
        for(int i = ;i < length;i++){
            for(int j = ;j <= i;j++){
                if(j == )
                    result[i][j] = result[i-][j] + triangle[i][j];
                else if(j == i)
                    result[i][j] = result[i-][j-] + triangle[i][j];
                else
                    result[i][j] = min(result[i-][j],result[i-][j-]) + triangle[i][j];
            }
        }
        int min_num = 0x7FFFFFFF;
        for(int i = ;i < length;i++){
            if(result[length-][i] < min_num)
                min_num = result[length-][i];
        }
        return min_num;
    }
};