1780: 简单的图论问题?

#include<string>
#include<math.h>
#include<stdio.h>
#include<iostream>
#include<queue>
#include<algorithm>
#include<vector>
#include<string.h>
#include <stdlib.h>
#include<iterator>
using namespace std;
typedef unsigned long long ll;

const int maxn = 505;
const int inf = 100000;
int vis1[maxn][maxn];
int vis2[maxn][maxn][4];
int a[maxn][maxn];
int n,m,r1,r2,c1,c2;
struct node{
    int x,y,dir;
    int step;
};
bool operator<(node a , node b){
    return a.step > b.step;
}
int to[4][2] = {1,0,-1,0,0,1,0,-1};
int bfs1(){
    if(c1 == c2&& r1 == r2)
        return 0;
    priority_queue<struct node> que;
    memset(vis1,0,sizeof(vis1));
    node no,nxt,now;
    no.x = r1 ; no.y = c1 ; no.step = a[r1][c1];
    que.push(no);
    vis1[r1][c1] = 1;
    while(!que.empty()){
        now = que.top();
        que.pop();
        if(now.x == r2&&now.y == c2)
            return now.step;
        for(int i = 0 ; i < 4; i ++){
            nxt.x = now.x + to[i][0];
            nxt.y = now.y + to[i][1];
            if(nxt.x>0&&nxt.x<=n&&nxt.y>0&&nxt.y<=m&&a[nxt.x][nxt.y]!=0&&!vis1[nxt.x][nxt.y]){
                vis1[nxt.x][nxt.y] = 1;
                nxt.step = now.step + a[nxt.x][nxt.y];
                que.push(nxt);
            }

        }
    }
    return -1;
}

int bfs2(){
    if(c1 == c2&& r1 == r2)
        return 0;
    priority_queue<struct node> que;
    memset(vis2,0,sizeof(vis2));
    node no,nxt,now;
    no.x = r1 ; no.y = c1 ; no.step = a[r1][c1];
    no.dir = -1;
    que.push(no);
    vis2[r1][c1][0] = vis2[r1][c1][1] = vis2[r1][c1][2] =vis2[r1][c1][3] = 1;
    while(!que.empty()){
        now = que.top();
        que.pop();
        if(now.x == r2&&now.y == c2)
            return now.step;
        for(int i = 0 ; i < 4; i ++){
            nxt.x = now.x + to[i][0];
            nxt.y = now.y + to[i][1];
            if(now.dir==i)
                continue;
            if(nxt.x>0&&nxt.x<=n&&nxt.y>0&&nxt.y<=m&&a[nxt.x][nxt.y]!=0&&!vis2[nxt.x][nxt.y][i]){
                vis2[nxt.x][nxt.y][i] = 1;
                nxt.step = now.step + a[nxt.x][nxt.y];
                nxt.dir = i;
                que.push(nxt);
            }

        }
    }
    return -1;
}

int main()
{
    int i,j;
    char ch[5];
    int k = 1;
    while(~scanf("%d%d%d%d%d%d",&n,&m,&r1,&c1,&r2,&c2)){
        for(i=1;i<=n;i++){
            for(j=1;j<=m;j++){
                cin>>ch;
                if(ch[0] == '*')
                    a[i][j] = 0;
                else
                    a[i][j] = atoi(ch);
            }
        }
        cout<<"Case "<<k++<<": ";
        int res1 = bfs1();
        int res2 = bfs2();
        printf("%d %d\n",res1,res2);
    }
    return 0;
}

1784: Internet of Lights and Switches

#include<iostream>
#include<stdio.h>
#include<string.h>
#include<math.h>
#include <algorithm>
#include <map>
#include <vector>
using namespace std;
typedef long long LL;
char str[80];
const int INF = 999999999;
map<LL,vector<int> > mp;
int n,m,A,B;
LL charToLL(char *str){
    LL ans = 0;
    int p = 1,len = strlen(str);
    for(int i=len-1;i>=0;i--){
        if(str[i]=='1'){
            ans+=p;
        }
        p*=2;
    }
    return ans;
}
int binary(LL val,int id){
    vector <int> vec = mp[val];
    int down = 0,up = vec.size()-1,r=-1,l=INF;
    while(down<=up){
        int mid = (down+up)>>1;
        if(id-vec[mid]>=A){
            r = mid;
            down = mid+1;
        }else up = mid-1;
    }
    down = 0,up = vec.size()-1;
    while(down<=up){
        int mid = (down+up)>>1;
        if(id-vec[mid]<=B){
            l = mid;
            up = mid-1;
        }else down = mid+1;
    }
    //printf("%d %d\n",l,r);
    if(l>r) return 0;
    return r-l+1;
}
int main(){
    int t = 1;
    while(scanf("%d%d%d%d",&m,&n,&A,&B)!=EOF){
        mp.clear();
        for(int i=0;i<m;i++){
            str[i] = '1';
        }
        str[m]='\0';
        LL k = charToLL(str),xorsum=0,ans = 0;
        for(int i=1;i<=n;i++){
            scanf("%s",str);
            LL x = charToLL(str);
            xorsum^=x;
            if(xorsum==k&&i>=A&&i<=B) ans++;
            ans+=binary(k^xorsum,i);
            mp[xorsum].push_back(i);
        }
        printf("Case %d: %lld\n",t++,ans);
    }
}

1797: Train passengers

#include <iostream>
#include <stdio.h>
#include <string.h>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <vector>
#include <math.h>
#include <algorithm>
using namespace std;
#define ls 2*i
#define rs 2*i+1
#define up(i,x,y) for(i=x;i<=y;i++)
#define down(i,x,y) for(i=x;i>=y;i--)
#define mem(a,x) memset(a,x,sizeof(a))
#define w(a) while(a)
#define LL long long
const double pi = acos(-1.0);
#define Len 200005
#define mod 360000
const int INF = 0x3f3f3f3f;
#define exp 1e-6

int main()
{
    LL C,n,sum,w,a,b,c;
    w(scanf("%lld%lld",&C,&n)>0)
    {
        sum=0;
        w=0;
        int flag=0;
        w(n--)
        {
            scanf("%lld%lld%lld",&a,&b,&c);
            if(flag)
                continue;
            if(sum<a)
            {
                flag=1;
                continue;
            }
            sum=sum-a+b;
            if(sum>C)
                flag=1;
            if(sum!=C && c) flag = 1;
            if(!n && (sum || b || c)) flag = 1;
        }
        if(flag)
            printf("impossible\n");
        else
            printf("possible\n");
    }
}