hihocoder 1632 Secret Poems

题目链接：Secret Poems

题目大意：给你一个某种路径形成的字符串，还原后用另一种方法表示

题目思路：按题意模拟就好了，还原的时候分一下上下三角，然后上下三件移动的方向是成循环的，下半角需要分一下奇偶以确定初始方向

#include <map>#include <set>#include <cmath>#include <vector>#include <cstdio>#include <cstring>#include <cstdlib>#include <iostream>#include <algorithm>using namespace std;const int maxn = 1e6+10;int main(){    int n;    char mp[200][200];    while(~scanf("%d",&n)){        for(int i = 1;i <= n;i++)            for(int j = 1;j <= n;j++)                cin>>mp[j][i];        int x = 1,y = 1;        string dir = "R";        string str = "";        str += mp[1][1];        int flag = 0;        while(1){            if(x == n&&y == n) break;            if(x == n&&y == 1){                flag = 1;                if(n&1) dir = "D";                else dir = "LD";            }            if(flag == 0){//shang                if(dir == "R"){                    dir = "LD";                    x++;                    str += mp[x][y];                }                else if(dir == "LD"){                    if(y + 1 > n||x - 1 <= 0) dir = "D";                    else x--,y++,str += mp[x][y];                }                else if(dir == "D"){                    dir = "RU";                    y++;                    str += mp[x][y];                }                else if(dir == "RU"){                    if(x + 1 > n||y - 1 <= 0) dir = "R";                    else x++,y--,str += mp[x][y];                }            }            else{                if(dir == "D"){                    dir = "LD";                    y++;                    str += mp[x][y];                }                else if(dir == "LD"){                    if(y + 1 > n||x - 1 <= 0) dir = "R";                    else x--,y++,str += mp[x][y];                }                else if(dir == "R"){                    dir = "RU";                    x++;                    str += mp[x][y];                }                else if(dir == "RU"){                    if(x + 1 > n||y - 1 <= 0) dir = "D";                    else x++,y--,str += mp[x][y];                }            }        }        x = 1,y = 1;        int ct = 1,cnt = 1;        memset(mp,'*',sizeof(mp));        mp[1][1] = str[0];        dir = "R";        while(1){            if(cnt == n*n) break;            if(dir == "R"){                if(x + 1 > n||mp[x+1][y] != '*') dir = "D";                else cnt++,x++,mp[x][y] = str[ct++];            }            else if(dir == "D"){                if(y + 1 > n||mp[x][y+1] != '*') dir = "L";                else cnt++,y++,mp[x][y] = str[ct++];            }            else if(dir == "L"){                if(x - 1 <= 0||mp[x-1][y] != '*') dir = "U";                else cnt++,x--,mp[x][y] = str[ct++];            }            else if(dir == "U"){                if(y - 1 <= 0||mp[x][y-1] != '*') dir = "R";                else cnt++,y--,mp[x][y] = str[ct++];            }        }        for(int i = 1;i <= n;i++){            for(int j = 1;j <= n;j++){                printf("%c",mp[j][i]);            }            puts("");        }    }    return 0;}