hdu5353

模拟，，，

每个人有一些糖果，每两个人之间只能给一个糖果，问最后是否能让所有人的糖果数量相同，只要确定一个糖果的流向其他的就能够确定。

马虎了，卡了好几天，心塞塞的。。。

#include<iostream>
#include<string.h>
#include<stdio.h>
using namespace std;

const int maxa = 100005;
int biaoji[maxa];
int vis[maxa];
int put[maxa][2];
int ans(int a[], int n){
    int sta;
    int o = 0;
    for(int i =0;i < n; i++){
        if(a[i] > 0){
            sta = i;
            break;
        }
    }
    memset(vis, 0, sizeof(vis));
    int len = 0;
    int last = 0;
    for(int k = sta;; k++){
        if(len++ > n*3) break;
        int i = k % n;
        if(vis[i] == 1){
            last = 0;
            continue;
        }
        if(last == 1 && a[i] == 1){
            last = 0;
            continue;
        }
        if(a[i] > 0){
            last = 0;
            put[o][0] = i;
            put[o++][1] = (i+1)%n;
            vis[i] = 1;
            a[i] --, a[(i+1)%n] ++;
        }else if(a[i] < 0) last = 1;
    }
    /*for(int i =0 ;i < n; i++){
        printf("%d ", a[i]);
    }puts("");*/
    len = 0;
    last = 0;
    for(int i = sta; ; i--){
        i = (i%n+n*800)%n;
        if(len++ > n*3) break;
        if(vis[(i+n-1)%n] == 1)continue;
        if(a[i] > 0){
            put[o][0] = i;
            put[o++][1] = (i+n-1)%n;
            vis[(i+n-1)%n] = 1;
            a[i] --;
            a[(i-1+n)%n] ++;
        }
    }
    for(int i = 0;i < n; i++){
        if(a[i] != 0) return 0;
    }
    puts("YES");
    printf("%d
", o);
    for(int i = 0;i  < o; i++){
        printf("%d %d
", put[i][0]+1, put[i][1]+1);
    }return 1;
}
int ans1(int a[], int n){
    int sta;
    int o = 0;
    for(int i =0;i < n; i++){
        if(a[i] > 0){
            sta = i;
            break;
        }
    }
    memset(vis, 0, sizeof(vis));
    int len = 0;
    int last = 0;

    for(int i = sta; ; i--){
        i = (i%n+n)%n;
        if(last == 1 && a[i] == 1){
            last = 0;
            continue;
        }

        if(len++ > n*3) break;
        if(vis[(i+n-1)%n] == 1){
            last = 0;
            continue;
        }
        if(a[i] > 0){
            put[o][0] = i;
            put[o++][1] = (i+n-1)%n;
            vis[(i+n-1)%n] = 1;
            a[i] --;
            a[(i-1+n)%n] ++;
        }else if(a[i] < 0){
            last = 1;
        }
    }
    /*for(int i =0 ;i < n; i++){
        printf("%d ", a[i]);
    }puts("");*/
    len = 0;
    last = 0;
    for(int k = sta;; k++){
        if(len++ > n*3) break;
        int i = k % n;
        if(vis[i] == 1)continue;;
        if(a[i] > 0){
            last = 0;
            put[o][0] = i;
            put[o++][1] = (i+1)%n;
            vis[i] = 1;
            a[i] --, a[(i+1)%n] ++;
        }
    }
    for(int i = 0;i < n; i++){
        if(a[i] != 0) return 0;
    }
    puts("YES");
    printf("%d
", o);
    for(int i = 0;i  < o; i++){
        printf("%d %d
", put[i][0]+1, put[i][1]+1);
    }return 1;
}
int a[maxa], b[maxa], c[maxa];
int main(){
    int t;
    scanf("%d", &t);
    while(t--){
        memset(biaoji, 0, sizeof(biaoji));
        int n;
        scanf("%d", &n);
        long long sum = 0;
        int ok = 0;
        for(int i = 0;i < n; i++){
            scanf("%d", &a[i]);
            sum += a[i];
        }
        for(int i = 1; i < n; i++){
            if(a[i] != a[i-1]){
                ok = 1;
                break;
            }
        }
        int ook = 0;
        for(int i = 0;i  < n; i++){
            b[i] = a[i] - sum/n;
            c[i] = b[i];
            if(c[i] > 1)biaoji[i] = 1;
            else biaoji[i] = 0;
            if(b[i] > 2 || b[i] < -2) ook =1;
        }
        if(ok == 0){
            puts("YES
0");
            continue;
        }
        if(sum % n != 0 || ook){
            puts("NO");
            continue;
        }
        if(ans(b, n));
        else if(ans1(c, n));
        else puts("NO");
    }
}
/*
5
6
2 0 0  2 0 2
8
3 0 0 3 0 2 0 0
8
3 0 0 3 0 0 2 0
8
0 0 3 3 0 0 2 0
8
1000000000 1000000000 1000000000 1000000000 1000000000 1000000000 1000000000 1000000001
*/

 这是a过后花了二十分钟敲的不那么丑但依旧很丑的代码

#include<iostream>
#include<stdio.h>
#include<string.h>
using namespace std;
const int maxa = 100005;
int put[maxa][2], vis[maxa];
int ans(int n, int a[]){
    int sta= 0;
    for(int i = 0;i < n; i++){
        if(a[i] > 0){
            sta = i;
        }
    }
    memset(vis, 0, sizeof(vis));
    int len = 0, last = 0, o =0 ;
    for(int i = sta; ;i++){
        i = i%n;
        if(len++ > 3*n) break;
        if(vis[i] == 1){
             last= 0;
             continue;
        }
        if(last == 1 && a[i] == 1){
            last = 0;
            continue;
        }
        if(a[i] > 0){
            vis[i] = 1;
            a[i] --, a[(i+1)%n] ++;
            put[o][0] = i;
            put[o][1] = (i+1)%n;
            o++;
        }else if(a[i] < 0){
            last = 1;
        }
    }
    len = 0, last = 0;
    for(int i = sta; ; i--){
        i = (i+n)%n;
        if(len++ > n*3) break;
        if(vis[(i+n-1)%n] == 1){
            last = 0;
            continue;;
        }
        if(last == 1 && a[i] == 1){
            last = 0;
            continue;
        }
        if(a[i] > 0){
            vis[(i+n-1)%n] = 1;
            a[i] --, a[(i+n-1)%n] ++;
            put[o][0] = i;
            put[o][1] = (i+n-1)%n;
            o++;
        }else if(a[i] < 0) last = 1;
    }
    for(int i =0 ; i< n; i++){
        if(a[i]) return 0;
    }
    puts("YES");
    printf("%d
", o);
    for(int i = 0 ;i < o; i++){
        printf("%d %d
", 1+put[i][0], 1+put[i][1]);
    }
    return 1;
}
int ans1(int n, int a[]){
    int sta= 0;
    for(int i = 0;i < n; i++){
        if(a[i] > 0){
            sta = i;
        }
    }
    memset(vis, 0, sizeof(vis));
    int len = 0, last = 0, o =0 ;
    for(int i = sta; ; i--){
        i = (i+n)%n;
        if(len++ > n*3) break;
        if(vis[(i+n-1)%n] == 1){
            last = 0;
            continue;;
        }
        if(last == 1 && a[i] == 1){
            last = 0;
            continue;
        }
        if(a[i] > 0){
            vis[(i+n-1)%n] = 1;
            a[i] --, a[(i+n-1)%n] ++;
            put[o][0] = i;
            put[o][1] = (i+n-1)%n;
            o++;
        }else if(a[i] < 0) last = 1;
    }
    len = 0, last = 0;
    for(int i = sta; ;i++){
        i = i%n;
        if(len++ > 3*n) break;
        if(vis[i] == 1){
             last= 0;;continue;
        }
        if(last == 1 && a[i] == 1){
            last = 0;
            continue;
        }
        if(a[i] > 0){
            vis[i] = 1;
            a[i] --, a[(i+1)%n] ++;
            put[o][0] = i;
            put[o][1] = (i+1)%n;
            o++;
        }else if(a[i] < 0){
            last = 1;
        }
    }
    for(int i =0 ; i< n; i++){
        if(a[i]) return 0;
    }
    puts("YES");
    printf("%d
", o);
    for(int i = 0 ;i < o; i++){
        printf("%d %d
", 1+put[i][0], 1+put[i][1]);
    }
    return 1;
}
int a[maxa], b[maxa], c[maxa];
int main(){
    int n, t;
    scanf("%d", &t);
    while(t--){
        scanf("%d", &n);
        long long sum = 0;
        for(int i = 0;i < n; i++){
            scanf("%d", &a[i]);
            sum += a[i];
        }
        if(sum % n){
            puts("NO"); continue;
        }
        for(int i = 0;i < n; i++){
            b[i] = a[i] - sum /n;
            c[i] = b[i];
        }
        if(ans(n, b)) ;
        else if(ans1(n, c));
        else puts("NO");
    }
}