先看以下代码:
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#include <stdio.h>
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#include <string.h>
3![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
4![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
5![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
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int main()
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{
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int N = 0;
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int subValue = 0,MaxValue = 0;
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int iN = 0,jN = 0;
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int si,sj;
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int i,j;
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int ii,jj;
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15
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int Matrix[100][100];
17![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
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scanf("%d",&N);
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for(iN = 0;iN<N;iN++)
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{
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for(jN = 0;jN<N;jN++)
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{
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scanf("%d",&Matrix[iN][jN]);
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}
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}
26![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/dot.gif)
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}
将断点设在18行后,输入4,检查N的值,居然是:![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
2
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/dot.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif)
改变代码:
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/dot.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif)
而唯一正常的是如下代码:
即将所有N在函数体外声明便正常了,难道是C语言对函数体内的变量有个数限制?神秘现象解密中...