poj1804
简单题
View Code
#include
<
iostream
>
#include
<
cstdio
>
#include
<
cstdlib
>
#include
<
cstring
>
using
namespace
std;
#define
maxn 1006
int
n;
int
a[maxn], cnt, c[maxn];
void
input()
{
scanf(
"
%d
"
,
&
n);
for
(
int
i
=
0
; i
<
n; i
++
)
scanf(
"
%d
"
,
&
a[i]);
}
void
MergeSort(
int
l,
int
r)
{
int
mid, i, j, tmp;
if
(r
>
l
+
1
)
{
mid
=
(l
+
r)
/
2
;
MergeSort(l, mid);
MergeSort(mid, r);
tmp
=
l;
for
( i
=
l, j
=
mid; i
<
mid
&&
j
<
r; )
{
if
(a[i]
>
a[j])
{
c[tmp
++
]
=
a[j
++
];
cnt
+=
mid
-
i;
}
else
c[tmp
++
]
=
a[i
++
];
}
if
(j
<
r)
for
(; j
<
r;
++
j)
c[tmp
++
]
=
a[j];
else
for
(; i
<
mid;
++
i)
c[tmp
++
]
=
a[i];
for
(i
=
l; i
<
r;
++
i)
a[i]
=
c[i];
}
}
int
main()
{
//
freopen("t.txt", "r", stdin);
int
t;
scanf(
"
%d
"
,
&
t);
for
(
int
i
=
0
; i
<
t; i
++
)
{
input();
cnt
=
0
;
MergeSort(
0
, n);
printf(
"
Scenario #%d:\n%d\n\n
"
, i
+
1
, cnt);
}
return
0
;
}