hdu 5353 Average 迷のWA-- --

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题意：相邻两个人能传递一次糖果，问最后所有人的糖果数是不是一样。

把第一个给第二个的情况枚举一下，接下来剩下的人按情况即可。

按理说，依次判断 if (OK) { PRINTF; continue;}的写法和放在for里面根据case讨论第一个给第二个的情况是没有区别的，蓝而，，神奇的是前者会迷のwa-- --，顺便贴下AC代码

AC：

#include <bits/stdc++.h>#include <map>#include <set>#include <queue>#include <stack>#include <cmath>#include <time.h>#include <vector>#include <cstdio>#include <string>#include <iomanip>///cout << fixed << setprecision(13) << (double) x << endl;#include <cstdlib>#include <cstring>#include <iostream>#include <algorithm>using namespace std;#define lson l, mid, rt << 1#define rson mid + 1, r, rt << 1 | 1#define ls rt << 1#define rs rt << 1 | 1#define pi acos(-1.0)#define eps 1e-8#define Mp(a, b) make_pair(a, b)#define asd puts("asdasdasdasdasdf");typedef long long ll;typedef pair <int, int> pl;//typedef __int64 LL;const int inf = 0x3f3f3f3f;const int N = 100010;int a[N], c[N];ll sum, avg;vector <pl> v;int n;void OUT(){puts("YES");int sz = v.size();printf("%d\n", sz);for( int i = 0; i < sz; ++i ) {printf("%d %d\n", v[i].first, v[i].second );}}int f(){for( int i = 2; i <= n; ++i ) {int j = i+1;if( j == n+1 )j = 1;if( abs( c[i]-avg ) > 1 )return 0;if( c[i] < avg ) {c[i]++, c[j]--;v.push_back( Mp( j, i ) );}else if( c[i] > avg ) {c[i]--, c[j]++;v.push_back( Mp( i, j ) );}}for( int i = 1; i <= n; ++i )if( c[i] != avg )return 0;return 1;}int main(){int tot;scanf("%d", &tot);while( tot-- ) {scanf("%d", &n);sum = 0;for( int i = 1; i <= n; ++i ) {scanf("%d", &a[i]);sum += a[i];}if (sum % n) {    printf("NO\n");    continue;}if (n == 1) {    printf("YES\n");    printf("0\n");    continue;}avg = sum / n;bool OK = 0;int p;for( int i = 0; i < 3; ++i ) {v.clear();memcpy( c, a, sizeof c );if( i == 1 ) {c[1]--, c[2]++;v.push_back( Mp(1, 2) );}else if( i == 2 ) {c[1]++, c[2]--;v.push_back( Mp( 2, 1 ) );}OK = f();if( OK ) {OUT();break;}}if( OK == 0 )puts("NO");}return 0;}

wa：（保证其他地方都一样），然后wa3、 40+发

avg = sum / n;        int OK = 0;        v.clear();        memcpy( c, a, sizeof c );        c[1]++, c[2]--;        v.push_back( Mp( 2, 1 ) );        OK = f();        if( OK ) {            OUT();            continue;        }        v.clear();        memcpy( c, a, sizeof c );        c[1]--, c[2]++;        v.push_back( Mp( 1, 2 ) );        OK = f();        if( OK ) {            OUT();            continue;        }        v.clear();        memcpy( c, a, sizeof c );        OK = f();        if( OK ) {            OUT();            continue;        }        if( !OK ) {            puts("NO");        }

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